1
"Well done, team Japan!" The inexhaustibly excited announcer began the morning news. "Good morning, today is Friday, June the twenty-seventh. I think we'll start the day on football!"
The TV in the living room was showing the highlights of a world cup match that had taken place on the other side of the world. It was the second group league match, which had been played late at night for Japan itself. It was just before halftime, and the Japanese team were a single point behind. Number 10 had dribbled the ball all the way up the pitch but was taken down by an overzealous defence from the opponents. The whistle pierced the stadium and they were given a free kick from just behind the penalty area.
Number 4 placed the ball down and backed up step-by-step. You could feel the tension, even through the screen.
Sakuta watched the screen absently.
"I've… seen this."
He wouldn't have watched a late-night game live. Sakuta had watched these highlights yesterday morning. The ball would go past the keeper and find its home in the netting of the goal.
Holding his breath, Sakuta watched the highlight. The ball arced through the trajectory just as Sakuta had remembered it, flying into the goal.
They had drawn even and their opponents were chewing their lips in consternation. Number 4 gave a roar of triumph, echoed by the other players and their supporters.
With the momentum of that goal, the Japanese team had gained an additional point in the second half and maintained that lead to a glorious victory.
The results played out just as he remembered them, so to reassure himself of his control over himself he stuck his head back in his room to check his alarm clock. It sat at the side of his bed, its digital display showing the date as well as the time.
June 27th.
The same as the announcer had just reported.
"What… on Earth…" From what Sakuta remembered, it should by the twenty-eight. And yet both the TV and the clock said it was the twenty-seventh. So today was yesterday, and yesterday was today. "…I see, a dream."
Sakuta got back into bed, covered himself in the quilt again and went back to sleep.
If today was yesterday, he could sleep until tomorrow. Just as he had that thought and had closed his eyes, the door clicked open.
"Onii-chan, weren't you just up?" He heard his sister's voice. She approached with a quiet patter of footsteps. "You can't go back to sleep, wake up."
She shook him.
"I'm sleeping until tomorrow."
"You're alright with missing school?"
"Yeah."
"Then I'll sleep with you," she said, burrowing her way into the quilt as she did.
"I'll get up then."
He rose abruptly.
"Eh? So quickly!?"
He stood, almost like he was passing Kaede on her way into the bed wearing her panda pyjamas. He moderated his escapism and returned to the living room. The morning news was still talking about the football.
Kaede came pattering in just behind him.
"Hey, Kaede."
"Yes?"
"I'm going to ask something kind of weird."
"I-it's not anything perverted, is it?"
"It's not."
"Y-you can't do something like that, Onii-chan," she said as she squirmed and covered her face, not listening to him.
"Did you see this report yesterday?"
"…The football report?" She asked, peeking through a gap in her fingers.
"Yes."
"Umm, I didn't?" Kaede almost asked, confused at what he was questioning and frowning slightly.
"I figured… that's fine then."
As he answered, Sakuta felt a sense of unease brewing in his stomach, like he was about to get involved in something bad.
Still feeling like he was in some kind of delusion, Sakuta ate breakfast with Kaede, and still not understanding, left for school.
Maybe it'd become clear if he went outside, he thought.
"See you later, Onii-chan."
Kaede watched him leave with a smile. Unlike his usual habit, he headed towards the station while paying careful attention to his surroundings. He walked past the flats and detached houses that lined the streets, by the side of the park and crossed the bridge that came into sight onto the main street. As he approached the station itself, his sight was filled with business hotels and electronics wholesalers.
Throughout Sakuta's journey, there was nothing that stuck out to him. There were other commuters heading to the same Station as him, housewives putting out the rubbish and even the old man that ran the flower shop cleaning up around the store.
It had taken him around ten minutes to walk to Fujisawa Station, right in the middle of the city by the same name, in the Kanagawa Prefecture. There were crowds of commuting workers and students walking to and fro around the area. The workers were transferring to the Tokaido Line and the Students were streaming through the Odakyu ticket gate towards the Fujisawa Enoden station, the same as Sakuta would be. None of them seemed to falter in their walks, just briskly proceeding towards their destination. None of them even spared a sideways glance, Sakuta was the only one looking around restlessly, watching others' actions.
"Is it just me…?"
As he passed through the ticket gate, he could feel a sense of unease prickling under his skin that that was indeed the case.
He waited on the platform for two minutes before boarding the train as it arrived. It was old-fashioned, only four carriages long. The bell rang to warn of the doors closing and the train pulled away.
After being rocked by the train for about fifteen minutes, they had arrived at Shichirigahama Station on the coast, a few minutes walk from Minegahara High School, the school Sakuta attended. Other students in the same uniform milled out onto the platform. The scent of the salty sea breeze hit Sakuta as he stepped outside, a sign of the approaching summer. In another ten days, the beaches nearby would be opened and filled with people going to swim in the ocean.
When he looked towards the sea, he could see several sails of windsurfers that were making the most of the clear day within the rainy season. It was a familiar sight, with nothing particularly odd about it.
The short road to the school was the same as always, packed with Minegahara High School Students. There were first-year boys messing around with their classmates, third-year students with textbooks in hand, girls chattering about the karaoke night they'd had after school the night before…
Everywhere he looked, Sakuta could see nothing but the usual sights.
There wasn't a single conversation like:
"Hey, isn't this the second time today happened?"
"Right? Me too, me too!"
"It's seriously freaking me out."
It was only Sakuta that walked in a daze, confused at a second twenty-seventh of June.
"'Sup, Sakuta. You've got bed-head again," one of his only two friends, Kunimi Yuuma, called out to him after he passed through the school gate and in to the school proper.
Yuuma had come from training with the basketball club, and was wearing knee-length jogging shorts and a T-shirt. There were many students in sports clubs that would go to lessons in that kind of outfit and not wear their uniform for the entire school day, Yuuma was one of them.
"It's a hairstyle."
"A fresh trend, huh?" Yuuma returned with a smile. This was normal too… in fact, Sakuta remembered this conversation, it was exactly the same as the one he remembered from 'yesterday'.
Sakuta fell silent.
"What's up, Sakuta?"
"…Nothing."
"Seriously, what is it?"
"I'm just pissed off you're so popular."
"Huh? What's with that?"
Sakuta said nothing about how this was the second time the day had happened and just followed the conversation along until they reached the classroom.
The four classes Sakuta had that morning, Maths, Physics, English, and Japanese, along with the topics covered were also identical to yesterday. Even the Maths teacher sing-songing "This'll be on your exam", the Physics teacher's lame jokes, the English teacher's "Listen to me, Mister Azusagawa" and the lipstick on the Japanese teacher's collar were all the same as Sakuta had experienced 'yesterday'.
As time passed, Sakuta's doubts began to solidify into conviction.
Just my memories returned to yesterday.
That concept turned the seemingly peaceful scenes of the classrooms into something eerie. Was it the world that had gone mad, or Sakuta himself?
"It's the world, obviously," he said to himself.
His body felt entirely normal, grounded in reality, with nothing making it seem like he was in a dream.
Still wrestling with this, lunch arrived.
"If today is yesterday…"
Sakuta had an important promise to fulfil that lunch break, and so to make sure of that, he left the second year classroom.
Ten minutes later, Sakuta was sitting within an open classroom on the third floor of the school. The sea was visible from the window, and sitting across the desk from him was Sakurajima Mai, a third-year student and his senior.
She had a cool expression on her beautiful face. Her looks would put actresses to shame… actually, she was an actress herself, a performer with pure talent that had acted since her childhood. She was a celebrity with nationwide fame. For the last year or so, she had been on a hiatus but had recently resumed her activities.
Atop the desk between them was a lunch that she had made for Sakuta, the same food that he had eaten the day before.
Seasoned and fried chicken, fried eggs, seaweed and simmered beans, and potato salad garnished with cherry tomatoes.
Item by item, he used his chopsticks to ferry them to his mouth to taste. They were slightly under-seasoned, but they all had gentle flavours. It wasn't just the appearance, the taste itself was the same as in his memories.
In utter confusion at what was happening, Sakuta didn't say a word.
"Does it not taste good?"
"Hm?"
Sakuta raised his head in response to Mai's voice, meeting her frowning eyes. She wasn't hiding her displeasure in the slightest and her glare was beating into him. Lost in thought, Sakuta had completely forgotten to give his impressions of the lunch. Or rather, because he had the memory of having done so, he'd thought that he had already.
"It's really tasty," he assured her.
"It doesn't look like you think that at all."
"It really is. So much so I want to eat it every day."
"I won't be taken in by some Showstyle proposal. What exactly were you thinking while you were eating my lunch?"
Mai was sharp.
"I was just chewing over how happy being able to eat your cooking made me."
He didn't think he should speak to Mai about what was going on in this situation. He himself didn't really know what was going on, so telling Mai his vague impressions like that would just make her worry needlessly.
"Hmmm," Mai noised doubtfully.
"Mai-san, can I ask you something strange?"
"Something perverted?" Kaede had done the same, why did everyone always jump to that, it was vexing in the extreme. "I won't tell you what colour underwear I'm wearing."
"I'm enjoying myself just imagining that, so it's fine."
"Uwah, you creep," he'd meant it as a joke, but Mai recoiled, "so, what was the weird thing?"
"What am I to you, Mai-san?"
"Just a cheeky junior," she answered without a moment's hesitation, making sure to emphasise the 'just' to bother Sakuta.
"…I see. Then what do you think you are to me?"
"A beauty… that you have an unrequited love for, your very kind senpai that you long for from the bottom of your heart."
"That's right," as he spoke he ferried some egg to his mouth and chewed on it. It was an awful shame, but the relationship between them had returned to what it was before, even though she had agreed to go on a date with him before.
They should have been boyfriend and girlfriend, but he had regressed back to being a cheeky junior. However, if some strange phenomenon was getting in the way of Sakuta's romance, he just had to get another date with Mai.
He couldn't start sulking at a setback that was this minor, surrender was unthinkable.
"That really was a strange question, seriously, why?" Mai looked doubtfully at him.
"I thought I should make sure I know what the situation is before going forwards," Sakuta dodged the question with what seemed like a plausible reason. He hadn't lied, he really did want to know what was going on with this incomprehensible situation.
"I sort of doubt it," Mai said as she narrowed her eyes, peering at his face.
"More importantly, Mai-san."
"Don't avoid the topic."
"I love you, please go out with me," Sakuta continued as if he couldn't hear her.
Mai kept staring steadily at him.
"I said don't avoid the topic."
"I'd rather you didn't ignore my confession too."
"I'm tired of hearing it though."
"I see… it's a failed love then. I guess I'll have to look for someone else then."
"Hey, w"
"Thank you for everything until now," he interrupted her with a polite bow and a deep, disappointed sigh of unrequited love.
"I-I didn't say no… What, are you giving up!?" Mai glared at him with a pout.
"You will then?"
"Ugh… you're so cheeky even though you're just you."
"You will?" He asked again, not giving up.
"…Yeah," she answered in a barely audible voice with a small nod, "I will."
Then, as if to hide her embarrassment, Mai wordlessly stuffed a fried egg in her mouth. It was such an adorable act that Sakuta felt a chill go through his body.
"Mai-san."
"W-what?"
"Can I hug you?"
"What's your reason," Mai asked guardedly, her eyes upturned as she peeked at him.
"Because you're really cute right now."
"No then, absolutely not."
"Ehh?"
"You look like you'd just use that and push me down… Besides, that's not something I can just say 'yeah, sure' to."
Mai's grumblings continued from there.
Their lunch date drew to a close with the warning bell for classes and the pair of them parted to their respective classrooms.
During his journey, Sakuta saw someone familiar on one of the landings on the staircase he took. She had a short bob-cut as was currently in vogue, and a faint dusting of makeup on her cheeks to add a hint of colour, giving a soft impression of her overall expression.
Her name was Koga Tomoe.
She was a student in the year below Sakuta that had mistaken him for a pervert. The meeting had left an impression so he could remember her name. At the time, he had just been trying to help a lost child find her mother, an act purely out of the kindness of his heart, but even so, she had yelled 'Drop dead, you lolicon pervert!' and given him a sharp kick to the backside.
She was the same person, but seemed to have her head meekly down. Looking more closely, he saw that she was standing in front of someone. A tall, slim boy. He was still well built and was probably in a sports club. He had brown hair, and had trodden down the heels of his indoor shoes. His uniform was rather worn, so he was probably a third-year, the quintessential good looking guy.
"Maesawsenpai… what did you want to talk about?" Tomoe looked up nervously. Apparently, the male was called Maesawa.
"Say, would you like to go out with me?"
"Eh!?"
"You don't want to?"
"ah, um, uh… let me think about it for a while," Tomoe replied in disarray.
"Got it, I'll wait for your answer," Maesawa replied smoothly before climbing the stairs. Bumping into him would be bothersome, so Sakuta quickly stepped out into the corridor.
"She's popular. Well, she's cute," normally Sakuta would have hoped it ended poorly, but was in the mood to celebrate others' happiness today. After all, he'd gotten Mai to agree to date him. "Now… if only tomorrow comes, things'll be perfect."
That was Sakuta's greatest worry right now.
That night, Sakuta had tired of doing the same thing, so decided to put an idea into practice, an all-nighter.
When he had woken that morning, it was to the day before, so what would happen if he didn't sleep? So all he would have to do is not sleep and wait until tomorrow.
When it reached two in the morning, Sakuta bit back a yawn as he turned the TV on for a distraction. A football match was playing out on the screen. The players were wearing dark blue shirts, so they were the Samurai Blue, Japan's national team, and their first string as well.
"Seriously, they're playing two days running…" Even if they had a packed schedule, the rules should mean they had at least three days between each match… "Hmm?"
Something drew Sakuta's attention. As he watched the match develop, he realised what it was.
"I've seen this," he murmured to himself.
It was just before the first half finished… Number 10 took a pass in the centre and dribbled the ball rapidly up the pitch into the opposing team's half. As he dodged two players, one of their opponents kicked him from behind. The whistle blew just a little before the penalty area, giving Japan a chance at a free kick.
It was the same scene he had watched that morning on the news highlights. But the word LIVE was emblazoned across the upper right of the screen, so what was being shown was a satellite transmission from the match as it happened at that very moment, on the opposite side of the Earth.
"…That's a funny joke." He rushed back to his room to check the clock. Together with the time of ten minutes past two in the morning, the date 'June 27th' was displayed on its face.
Sakuta didn't say a word. He had let his guard down, thinking it was already tomorrow, and instead returned to yesterday.
Going back to the living room, Sakuta watched the match. At the referee's whistle, Number 4 took a run up and kicked the ball. The ball would find its home in that net… but just as that seemed inevitable, the powerful shot rebounded out onto the field from the crossbar, where it was swept up and cleared by a tall opposing defender, denying Japan the point.
"Huh? What?" Things had gone differently than Sakuta had thought, and he remembered a conversation he had had with his friend, Futaba Rio.
"So, it's like… if the Japanese football team have a match and if I just check the news then they won, but if I went and watched they lost?"
"You should never watch football again for the sake of our team. Don't look twice."
That was when they were talking about something like… observation having an influence on the result, he thought.
"No, there's no way…"
Just watching the match wouldn't make Japan lose.
Practically praying for them, Sakuta kept watching the match until the final whistle, supporting them. Japan couldn't make up their one point lag and finished the game that way, losing with a score of 0-1.
The newscaster and live commentator looked back on several of the team's near misses. Speaking of how the team had the bad habit of not following through on the decisive moments… it was a weak point of the Japanese team that was often talked about.
The newscaster informed Sakuta about how the team now had to win the next match they had with a veteran country to get out of the group leagues.
"I'll have to speak to Futaba about this tomorrow… I guess it's today actually, but also yesterday…"
Sakuta could do nothing but hold his head in his hands as he sat alone in the living room in the depths of the night.
2
In the end, Sakuta realised that his vigil was meaningless and so slept soundly until the morning… where he still hadn't given up and stubbornly turned the TV on, where Japan's narrow defeat was being broadcast again.
"It's really not my fault, right?"
With an oddly guilty conscience, Sakuta left thirty minutes earlier than usual.
A mere thirty minutes made the neighbourhood seem strangely different, like the air was somewhat cleaner, and with an odd change to the people milling around Fujisawa Station. There seemed like there were more workers. At his normal time, there were usually more uniform-clad students.
The familiar ride on the Enoden made that all the more apparent with the lack of passengers.
Obviously, the path from Shichirigahama Station to the school was empty. The passengers alighting at the station didn't number more than Sakuta himself. In rush hour, Minegahara students would form a column and parade along the road.
It felt like another place entirely.
Sakuta changed into his indoor shoes in the deserted entrance hall. The lack of people changed the atmosphere of the school, it was dead quiet and could probably be called tranquil.
As he took in those differences, Sakuta passed by the stairs and headed for the physics lab.
"Futaba, you here?" He questioned as he opened the door.
The girl in question was in front of the board. She was a petite girl, wearing a white coat on top of her uniform. This was one of Sakuta's only two friends… Futaba Rio.
She didn't spare Sakuta a glance and instead gave a melancholic sigh. Regardless, Sakuta took a seat opposite her across the desk.
On the surface between them was a beaker with toast placed atop it, and a coffee cup with steam curling from it. The toast had dark lines in it from the grill. Apparently, she was about to have breakfast. The science club was a little too laid back with Rio as its only member. Rio bit into the piece of toast in her hands, releasing the scent of warm bread with a crunch.
"Say," Sakuta started.
"No."
"I didn't even say anything yet," he protested.
"You've gone out of your way to come here so early, it's going to be something irritating, right?"
She really was sharp, he thought. But then again, anyone would know something was wrong in this situation.
"I come bearing news of a fascinating phenomenon."
"And that's exactly what I mean by irritating," Rio waved him off, unreachable, "go away."
Rio nibbled angrily at the crust of her toast. She was normally dispassionate, but she was particularly prickly today so was probably in a bad mood in the first place.
"What about you actually, did something happen?" Sakuta was concerned about it, so asked after her first.
"Why do you think that?" Rio finally looked at him, her eyes peering vigilantly from behind the lenses of her glasses.
"'Cause you're pissed."
"I'm not…" but as she denied it, she seemed to give up on evading the question and gave a long sigh, "Well, I guess lettering you laugh at it is better than just worrying about it alone."
Rio seemed to be muttering to herself as she looked off into the distance.
"The hell?"
She seemed unsure whether to be positive or negative about it.
"I rode the train with Kunimi this morning."
"Did he try and grope you?" Sakuta asked, his gaze inevitably dropping to her full breasts.
"Kunimi wouldn't do that."
"Stop looking at me like you want to say 'unlike you'."
"Don't look then," Rio said as she moved sideways to try and hide her chest. She obviously didn't like it, so Sakuta decided to make as much effort as he could to not look.
"And so? You rode the train with Kunimi and then what?"
"Then nothing, I just… I just dislike myself for being happy that a boy with a girlfriend spoke to me." Rio said with a self-deprecating smirk.
"That's just a girlish concern."
"And if you had spoken to me, it would have just been a fly buzzing in my ear."
"Was that really necessary?"
It definitely wasn't in his opinion, but then if he could anger her out of her funk, it didn't really matter.
"I guess I'm getting worse and worse."
Rio put the last of the crust in her mouth and took a long draught from her coffee cup before letting out a deep breath.
"What if you just say it?" Sakuta suggested.
"Say what?" Rio asked in turn, trying to slip past the question even though she knew exactly what he meant.
"'I like you.'"
"…To who?" She hesitated this time. Even if she asked, she knew what name would leave Sakuta's lips.
"To Kunimi, obviously," Sakuta told her, looking steadily into her eyes so she couldn't avoid it.
Rio pouted silently for a moment, and just when he thought she was going to turn sideways on her chair and look away from him, she spoke sulkily.
"I don't want your logic."
"Sorry."
"You should be."
"Are you going to just keep on like that, Futaba? I think you should do it before you get worse."
Sakuta knew that she bothered coming in so early for club activities so she could meet Yuuma. And yet, whether or not she could, she was like this.
"I said I don't want your logic," Rio sighed again, deeply enough fill an entire balloon, her expression melancholic, "if I did, it'd bother him."
"Go ahead and bother him, the chill bastard that he is."
"I wish I was as insensitive as you, Azusagawa."
"If you compliment me so much, I'll start blushing."
"I rest my case."
"Men are creatures that rejoice at girls abusing them."
"That's just low-lives like you," she retorted.
"Kunimi's girlfriend is pretty insensitive too.
She had said 'I feel sorry for Yuuma, being with an outcast like you' right to his face. However you looked at that, it was Sakuta people should feel sorry for, for having something like that said to him. Her name was Kamisato Saki. She was in the same class as Sakuta, 2-1, and while not his type, she was popular with the boys and known for her looks. She was the core of cute and popular clique in the class. The exact opposite of Rio, who was plain and made a habit of working away in the labs alone.
"Say, Azusagawa."
"What?"
"You really are insensitive, talking about her."
"You need desperate measures. If you don't like it, admit defeat already."
"Someone like you shouldn't be right."
Rio knew that that was the only solution. She knew that but didn't put it into practice, because if she put it into words, it would be over.
"I'm the only one that would say things like that."
"That you yourself admit that just makes you even worse," Rio smiled in faint amusement, her mood seeming to have changed some, "What did you want to speak about then?"
"I'm worried that tomorrow will never come."
"There's no bright future waiting for you anyway, so that's fine isn't it?"
He'd given a straight answer, but got a verbal shot in the gut as a result.
"It's not even slightly fine. I have a rosy future ahead of me." He'd start dating Mai this afternoon, so it was no exaggeration to call it a rosy future. "Anyway, today is yesterday and yesterday's today."
"Could you actually tell me in a way a human can understand?"
"I'm a human too," he defended.
"Even though you're a low-life pig?"
"Hey, that's… ah, whatever. Uhm…" Sakuta gave up arguing and started explaining the bizarre things that had happened to him from the beginning.
Five minutes later, when Sakuta had finished his explanation, Rio let out a sleepy yawn.
"So, what do you think, Futaba?"
"This is what they'd call Middle School Syndrome."
"I'm in high school though."
"Fine, it's High School Syndrome then."
"Man, that's lazy."
Rio was acting like it was all too much effort. She brewed herself another cup of coffee, and drank it on her own.
"If it's not some delusion, then is it that Adolescence Syndrome that you love so much?" Rio suggested, once more in a lazy tone of voice.
"I don't love it at all."
Adolescence Syndrome was the general name of a set of strange phenomena that were discussed on the net, false rumours of 'reading minds', 'having psychometry' and other such occultish things. No one seriously believed it. But, Sakuta had experienced several things similar to that. This might be the same, he couldn't think of any other explanation.
"Anyway, do something would you," Sakuta appealed.
"It's you that's going to have to do something."
"Why's that?"
"It certainly seems that I and the other seven billion people on the planet don't think that it's the third time today has happened."
Rio's sidelong glance at the grounds outside indicated the baseball team running around. They were dripping with sweat and certainly didn't seem to think that this was the third time. If they did, then they wouldn't be steadily working on their training.
"And this is about when I panic."
Rio had been using her phone and now showed the screen of search results. They keywords she had used were 'June 27th', 'third time', and 'repeating'. Unfortunately, there were no real hits.
"And so, I think this is probably an instance of Adolescence Syndrome caused by you," Rio spoke smoothly, giving Sakuta the unpleasant news.
"I'm not really mentally unstable enough for Adolescence Syndrome, and I'm not really under any stress." Those were the things suggested on the internet as causes of Adolescence Syndrome. The high stress from reality being against a person, or the illusion thereof, was the most likely explanation. In essence, it was an escape from reality.
"Well, it's fine if you're not self-aware," apparently Rio was certain that Sakuta was causing it, "whatever the cause, if you've got any other ideas as to what's going on, go ahead and say them."
"What do you mean?"
"If your explanation is everything, then I think you're looping through time."
"Yeah, that's about right," he answered.
Time-loops themselves were fairly common in Sci-Fi stories.
"It might be better if you didn't get caught up in that concept."
"Why?"
"There's a lot of problems with returning to the past," seeing as she didn't say that it was impossible meant that there was some theory for it, "the multiple days that are all 'June twenty-seventh' that you experience might seem like looking into the future from before that."
Rio had come out with an outrageous statement. It didn't seem like words that would come from a girl that had said it was difficult to go to the past.
"That sounds like you're easily accepting clairvoyance."
"It's far more likely than returning to the past."
"Seriously?"
"All that said, this is an idea from before quantum mechanics came into use… back from classical physics." Sakuta made a noise of consideration at Rio's words. "Have you heard of Laplace's Demon?"
"Unfortunately I'm not acquainted with any demons."
"If you don't know, that's fine… Everything that exists within this universe falls under the same laws of physics, that's fine, right?"
"Yeah, that's just physics, right?"
"It is. If you put those laws into formulae and carry out the calculations, you can predict the future state of a system."
It was a simple explanation, but it didn't seem to be the case in reality and so Sakuta cocked his head to the side.
"To put it clearly, if you knew the position and momentum of every atom… their mass and velocity that is, with those you could use classical formulae to derive their future state. It uses things that you learn in high school."
It was awfully unfortunate but Sakuta, despite going to the same school as Rio, didn't have the foggiest idea what she was talking about. There were a myriad of questions he wanted to ask to check things.
"All the atoms must be an absolutely huge number," he started with. The number must be high enough you could call it infinite.
"It is."
"So is it even possible to know all their positions and momenta?" It was hard to figure out how many grains of rice went into a rice-ball, let alone anything more.
"At the very least, back then… in the nineteenth century, the physicists couldn't do so. Even if they had been able to grasp all that information, calculating the results of the formulae from that vast amount of data would take a corresponding amount of time. So predicting a second in the future would take more than a second, so they couldn't predict the near future."
"I get that."
Modern computers would probably find it impossible too.
"So, the physicist Laplace thought of a fanciful existence that could do so."
"And that's Laplace's Demon?"
Rio nodded slowly before continuing.
"That demon has the ability to instantaneously know the positions and momenta of all atoms in existence, and to use that information to calculate the future. In other words, Laplace's Demon can see everything in the future."
"Hmmmm," Sakuta noised.
"You don't look like you agree."
"Nah, calculating the future would be fine, but then wouldn't our thoughts change it? Can you call that foresight?"
"Ah, so that's what it was."
"You can't predict emotions, right?"
"You can," Rio refuted clearly.
"Huh?" Was the only thing that could leave Sakuta's mouth.
"Human bodies are made of atoms as well. If you know each of their positions and momenta, you can derive how the brain will change or how the person will feel."
"I see… I wish I hadn't asked."
"If you follow through, you won't in the end."
"Really? But from what you said… if you take emotions into account, then knowing the position and momentum of every atom at that moment, you could predict how things would develop, right?"
"Right."
"Then wouldn't that mean that the future was set?" If you knew all of the positions and momenta of atoms then everything else was just a matter of time, there was no need to measure anything else. In other words, nothing but time would change. Physics and maths would set fate in stone.
"I'm impressed you realised that, well done, Azusagawa!" Rio praised him as if praising a child. "That's exactly right, that's what our conversation so far would imply."
"Then what? Whether or not I study for it, I'll get the same mark on the exam next week?"
"Not quite. The marks are certainly set. But it's not from the choice between studying or not, really, whether you study or not itself is already decided."
"Hmm, ah, yeah."
The future being set would mean that.
"Let's say that you decided 'the future is set, I won't bother trying' when you heard what I told you."
"Even then, wouldn't Laplace's Demon know I'd hear that and then try and fight against it?"
"Exactly."
It was complicated, but he got it. But then…
"Then aren't our fates predestined?" He asked.
"Have you forgotten what I started with?"
"That you were super happy Kunimi talked to you."
"Die."
"Umm… that it was 'from before quantum mechanics came into use', right?"
"If you remember, then don't take the mickey." Rio glared slightly peevishly at him. A girlish expression unthinkable from her normal frank attitude. "I explained Schrödinger's cat to you before."
"The one where the cat could be either alive or dead before you open the box?"
That was what he had heard when he was asking about what was happening with Mai's instance of Adolescence Syndrome.
"Well, good job on remembering that much."
"Praise me more."
Rio ignored him and continued.
"Do you remember that I explained that in quantum mechanics that the positions of atoms can only be determined probabilistically?"
"I do now. To fix the position, you have to observe it… That's it, right?"
"It is. So, that observation is the key, to see you need light."
Rio took out a torch from a drawer and shone it on a baseball on the desk.
"That's finding out the position of the atom then?"
"Right, but atoms are very small, so if they're hit with light, their velocity changes." Rio rolled the ball across the desk to the edge, where it fell and bounced twice, coming to rest at the chair leg. "And so, if finding an atom's position changes its velocity, which means that to know the velocity, and thus momentum means that the position becomes probabilistic again. There's no way to know both."
"That's irritating."
"And now it's clear that Laplace's Demon was eradicated by quantum mechanics, which is proof that the future isn't set. Aren't you relieved now?"
Honestly, he couldn't really feel relieved. Sakuta himself didn't really understand quantum mechanics and couldn't put his confidence in something he didn't really comprehend.
"But quantum mechanics is about human observation, right?"
"Of course it is."
"Then-"
"I know what you want to say, that Laplace's Demon is fundamentally beyond humans, so maybe it can know both," Rio opened her mouth and forestalled him with a confident gaze.
"Yeah, that's just what I wanted to say."
"You can decide just how much better the demon is than humans."
Rio seemed to have gone through this conversation just to say that, and at the same time was saying that Sakuta himself was Laplace's Demon.
"I'm not a wicked demon like that."
"Just make sure you don't get dissected."
"I'll be fine as long as you don't sell me out to some shady group of scientists."
"If I did that, maybe we wouldn't be able to meet anymore," Rio said with a glance down to her phone on the desk, "if you insist it's not you, you need to find the real Laplace's Demon."
"Where do you think it will be?"
They weren't taught how to find demons in their lessons at least.
"The demon, along with you, will have memories of the repeating days, right? Then they might well take different actions than they did the last June twenty-seventh I would guess."
"Ahh, I see…" Rio was exactly right, noticing that would make it fairly likely that the person would try to act against it, or be bewildered at the situation.
Although with that said, he had no real goal, not knowing where to search.
Sakuta shouldered his bag and stood, reaching out a hand to help Rio up, but she just said.
"Go ahead."
"Thanks then," he said, and as he got to the door and went to leave, he remembered something and stopped there, "Ah, right, Futaba?"
"What?"
"If today happens again, do you want me to make it so you don't meet Kunimi this morning?"
In that case, Rio wouldn't have looked so melancholic that morning.
Rio remained silent in thought for a moment.
"You don't need to worry," she said with a faint smile, "I'll be doing something myself about it."
"That's right, you owe me a lot, so I'll need to make sure you pay me back."
"I'll remember the interest too."
Sakuta left the physics lab behind as Rio watched him with a cynical smile.
3
"You need to find the real Laplace's Demon."
Rio had told him that, but where on Earth did he begin? He didn't have even an estimation of who the demon would be, and on top of that, there was no guarantee that it would be anywhere near him. At worst, it could be someone that lived on the other side of the world.
"It's the end if they are…"
He was a mere high school student, he didn't have the slack in their budget to cross the world or even have a passport. His prospects were grim. Actually, bleak would perhaps be a better term.
His mood had plummeted.
Even so, he headed to the third-floor classroom when lunch time rolled around to fulfil the promise to have lunch with Mai in the empty room.
Right now, the most important thing to Sakuta was dating Mai. Even that was being wiped from existence. Once more, that time would come for him to eat Mai's handmade food and confess to her. It had at least the one saving grace of being enjoyable in and of itself.
Sakuta cheerfully slid the classroom door open. At which point, he heard sounds from within what he was sure was a deserted classroom. Looking, he could see a skirt-clad backside in the shadows of the teacher's desk. Apparently, they were trying to hide themselves. A strong sense of foreboding ran down his back.
This hadn't happened the first or second times. On both occasions, Sakuta had arrived right at the start of lunch, followed slightly later whereupon they had an enjoyable lunch. Nobody had interrupted them, and Sakuta hadn't encountered anyone but Mai in the room.
And so this was a different development than the first or second times he had lived the day, the influence of someone taking different actions.
Rio's words from that morning passed through his mind.
"The demon, along with you, will have memories of the repeating days, right? Then they might well take different actions than they did the last June twenty-seventh I would guess."
And then in front of his eyes was a situation that fit those words to a T.
"There you are, Laplace's Demon," spoke Sakuta, and in response, the hiding girl timidly peeked her head out, like some tiny animal edging out of their nest and checking for danger.
Sakuta recognised that face. It was framed by a trending short bob cut and had large, round eyes and a dusting of makeup that gave a soft, cute impression. A 'with-it- aura emanated from her entire body, showing her to be a high school girl that fit the image conjured by the term, the high school girl.
She had her smartphone, with a salmon-pink case, in one hand, and her mouth was open to begin speaking. This was the first year, Koga Tomoe.
She was slight, even for a girl and there seemed to be not much to her, so she looked rather weak to be called a demon. She was an imp at best, a petite devil.
The sea breeze blowing in from the open window made Tomoe's hair and skirt sway slightly before she broke the silence.
"Satou Ichirou."
"That's an alias I use to hide from the world," Sakuta replied, surprised that she had remembered the fake name he had given when he first introduced himself. Apparently, she was the type that remembered someone's name when they met, unlike Sakuta.
"…You're Azusagawsenpai, yeah?" She asked, with an uncertain upward glance.
"Azusagawa Sakuta, second year."
"I am Koga Tomoe. A first year," she said, switching to a forced polite tone, giving a meeker impression.
"You can talk casually, we're backside-kicking-buddies after all."
"Forget about that!" Tomoe's cheeks puffed up into a pout, back to the image Sakuta had of her. Perhaps remembering the pain from then, Tomoe's hands covered her backside, taking a pose that didn't seem to fit an underclassman.
"Koga, I've got an awkward question."
"What?"
"How many times have you lived today?"
Tomoe's eyes opened wide at Sakuta's question, darting left and right in both surprise and a little unease.
"It's my third," he offered.
At that, she gave a nod and then said:
"It's my third too," raising three fingers. At that moment, her expression instantly morphed into tears and before Sakuta could even react carried on with, "It… wasn't just me."
Tears began to fall from her face and she fell to the floor out of either relief or being overwhelmed.
"What the hell is this!?" She yelled.
"Who knows."
"Why is the day repeating!?"
"I dunno."
"Why don't you know!?"
"I can't help not knowing things."
Her earlier relief went back to unease.
"I thought you could help me, give me back my tears!"
"Just go drink some water from the tap."
"What do I do now?" She asked, Sakuta actually wanted to ask that himself. "What'm I gonna do?" She asked again, in an unfamiliar tone. She didn't seem to understand the cause of the situation she was in, you could call her clueless.
"Why are you so calm!?" She demanded now, crapping hold of his collar and shaking him.
"Is panicking going to help?"
"It won't, but it's natural to."
"Is it?"
"It is, you're off, Senpai. I guess a deviant that confesses in front of the whole school would be though."
"I think calling someone else 'off' right to their face is plenty off as well."
"Shut uuup."
"Just in case you do, do you have any idea what's going on?"
"Not a clue."
"Nothing?"
"I-I don't know at all."
"You're useless."
"No, that's you!" She insisted.
"You had anything unpleasant or worrying on your mind recently?"
"Why do I have to tell you about that? Ah, a message." She immediately looked at her phone.
"Because… this seems like it's Adolescence Syndrome. If it's caused by an unstable mental state from you, solving that cause should solve this too."
"Adolescence Syndrome… Senpai, are you all there?" She asked mockingly, her gaze still fixed on her phone as she slid her fingers around the screen, busily tapping away. "That's just some rumour online. I can't believe you believe it."
The reason Sakuta believed it existed was because of his unbelievable experiences of such phenomena in the past.
The instance that involved his sister Kaede was the first. Just seeing the cruel posts and messages from her classmates caused bruises on her skin like she had been struck, and he had seen the cuts that looked like she had been sliced with a knife with his own eyes.
A month prior, he'd seen the circumstances around Mai, and forgotten her. And now, this situation followed the trend.
"I know how you feel, but after living the same day three times, I doubt that Adolescence Syndrome is just an urban legend.
"Ugh, that's right…" There was a limit to escaping reality and asking yourself if you were dreaming. With Tomoe in the same situation, it was getting more and more realistic. It might just be seeing the future as Rio suggested, but it certainly felt physically real.
"Also, quit messing while we're talking," Sakuta scolded as he yanked the phone from Tomoe's hands.
"Ah, give it back!" Tomoe shouted as she bounced and reached for the phone where Sakuta was holding it above her head, out of her short reach, "I won't talk and use it!"
She was admitting her fault, so he returned it.
"Here."
Like a cautious wild animal, she darted her hand forward and seized the phone, immediately starting to use it in silence.
The silence stretched between them for several moments.
"So you're stopping the talking?"
"Quiet, you're distracting me."
"Man, you girls."
And so, Sakuta waited for about twenty seconds.
"What was it then?" Tomoe asked, finally looking up from the screen.
"You had anything unpleasant or worrying on your mind recently? It might give us a hint on how to break through the twenty-seventh."
"…Hmmm." She furrowed her brow, thinking seriously, and after a good ten seconds, continued with a slight blush, deadly serious. "I've put on some weight."
Looking at her, Tomoe was rather dainty and slight. She could be called slender in multiple senses of the word.
"W-what are you looking at me like that for?" She questioned tremulously.
"It's okay. If anything, you're too thin anyway. If you put some weight on, you might get some meat on that washboard of yours."
"It all just goes to my stomach and backside."
Now that she said it, her waist and backside were both a reasonable thickness.
"Apparently they grow bigger if you fondle them."
"I've already tried that," she insisted, her hands unconsciously cupping her chest, headless of Sakuta's gaze.
"Give up then. Guys don't love girls for their chest anyway. Anything else? Something less pointless?"
"Swimming classes are starting so this isn't pointless at all! I don't have a bust, no hourglass figure, summer is hell…"
She seemed to be about to continue when her eyes went wide again and she went silent before letting out a small sound as she looked behind Sakuta… towards the corridor.
"H-hide!" She insisted, dragging him by the arms and pushing him under the teacher's desk.
"What are you playing at?"
"Just do it!"
Tomoe followed him into the narrow space under the desk. Practically straddling Sakuta as he lay on the floor.
This was probably some kind of game popular with the first years. Sakuta really didn't understand the youth.
His questions in mind, he looked at what was happening and could see a boy looking in from the open door. It was the third-year that had confessed to Tomoe on the last today… She'd called him Maesawsenpai, he thought.
"Pull your head in!"
Tomoe grabbed his face between her hands and pulled him back under.
"He's looking for you, isn't he?"
"I think so… but I sent a message saying I had some appointment this lunchtime…"
"An appointment? Doesn't look like you do," Sakuta teased liltingly.
"That's sorta what I said."
In other words, she'd lied to him.
"Quit beating around the bush, go get confessed to."
"How do you know about that!?"
"I saw you last time."
Tomoe's small face was right in front of Sakuta. The breaths coming from her glossy pink lips were tickling his cheeks and he shifted so that there wasn't any contact between the two of them in awkward places.
The motion startled Tomoe and she let out a slight scream as if she had been jabbed somewhere sensitive, but the cause was different. It was her phone vibrating in her hand, the backlight coming to life with another message.
"What kind of play is this supposed to be?" Sakuta asked.
Concentrating on her phone, Tomoe didn't reply.
While he was waiting for her to finish, his gaze drifted down and he noticed her skirt had ridden up and he could see the white cloth at the base of her right leg.
"Oi, Koga."
"Later."
"I can see your underwear."
"Now's not the time," she dismissed his warning.
"I don't get girls," he lamented.
Apparently, sending some message was more important than her sense of virtue. With no other recourse, he reached out and fixed her skirt for her. Now all he could see were her thighs.
In the meanwhile, she seemed to have finished her texting.
"Why are we hiding?" He asked.
There shouldn't have been any need for Sakuta to hide as well.
"Because… Renchan looks up to Maesawsenpai," Tomoe answered in a quiet voice, her gaze saying 'you should get it now'. Sakuta, on the other hand, didn't understand at all and so of course answered with:
"Huh?"
Tomoe parroted him before questioning him.
"How can you not get it?"
"Because you've not really explained it."
"Well, um… I often go with Renchan to watch the basketball club practice."
"And who's this Renchan again?"
She was probably some nationally famous actor or something.
"My friend… Kashiba Renchan. She said he's handsome and… I just go with her…"
At that point, Tomoe started mumbling.
"And you're more his type?"
"…Y-yeah," she said with a slow nod.
"And do you like him?"
"No… I don't like popular guys."
"Then go get confessed to and reject him."
There was no need to keep hiding, she just needed to reject him. The cultural festival was approaching, so it would be fitting for a handsome guy that seemed like he'd suddenly start a band to get rejected.
"That'd definitely get me ostracised! He's the one that Renchan…'s friend likes, you know?"
"Huh? What's that about, it's not like you'd be dating."
"Obviously I can't get confessed to by him."
"I don't get what you mean."
"I promised Renchan that I'd support her… and then if I got confessed to, that'd be completely missing the point," Tomoe's voice grew serious, "seriously, what do I do…?"
Her face had paled and it certainly seemed like a crisis to her, from the bottom of her heart.
"Did you give him the doe-eyes and seduce him that way?"
"Of course not!"
"We'll get caught if you yell."
She was taken aback and now, albeit too late, covered her mouth with her hands.
"anyway, you get it now, right?"
He understood what she'd said, but couldn't reconcile her sense of values.
"Not in the slightest."
"Jeez, there's no point talking to you!" Tomoe rose with her emotions. But of course, they were under the desk so she had to watch her head.
"Ah, wait…"
Sakuta's immediate warning was too late and Tomoe's head thunked into the desk. The impact was strong enough that it lifted off two of its legs, tipping away from the board.
Tomoe was too slow to reach for it when she noticed, her hand whirled through the air, and the desk fell over with an almighty crash.
Tomoe herself fell over, her feet caught in Sakuta's legs where he was lying on the floor and she lost her balance, falling with a cry.
Reflexively, Sakuta put his arms out to catch her. She was incredibly light, and definitely didn't need to worry about her weight.
"Honestly, you…"
He was going to finish it with 'should calm down a little', but couldn't end the sentence, because as he spoke he saw someone.
He met the gaze of a boy in the doorway, the third-year he had seen earlier. Maesawsenpai, who was apparently in the basketball club.
The boy's expression was unclear, with hints of confusion. It was understandable, from his point of view, Sakuta and Tomoe were holding each other on the floor of an empty classroom.
"So this is what you mean. You have crap taste."
Apparently, he had massively misunderstood things. On top of that, he was being rather rude.
"No, that's not…" Sakuta began to try and explain, but his voice died out as he heard a sound from the other door into the room.
His heart pounded in his chest, an unconscious reaction accompanying his panic. His instincts were screaming at him.
Even without turning to check who had made the noise, Sakuta knew, he knew all too well.
Haltingly, he turned to look.
Just as he thought, Mai was standing there.
There was a paper bag in her hand, containing the lunch she had made him. He even knew what was in that lunch, seasoned and fried chicken, fried eggs, seaweed and simmered beans, and potato salad garnished with cherry tomatoes…
He knew all of that, but he was also sure that he wouldn't be able to sample them today with a look at Mai's eyes.
She hadn't moved a single step from the door and was watching him with cold eyes. Watching as he held Tomoe… Watching with an expression of complete disinterest…
"This is a misunderstanding," Sakuta tried to give her the cold hard truth. His mettle was being tested here, all he could do was remain calm and explain the reality of the matter without yelling.
She gave no reply.
He looked her right in the eyes, visually proclaiming his innocence.
But she turned wordlessly on her heel.
"Argh, wait, Mai-san!" He cried, pushing Tomoe to the side and rushing to his feet. Ignoring Tomoe's own cry of pain as she hit her head on the desk on the floor, "Please let me explain."
"Don't talk to me, you lolicon philanderer."
Those were the only words she spared him before walking away.
"Argh, she's seriously mad."
They definitely wouldn't be eating together now, and confessing and getting something like 'yeah, sure' would be even harder.
He let out a sigh of resignation.
When he checked the other door, Maesawsenpai had left too. Tomoe was still on the floor so he offered her a hand up.
"T-thanks."
He then put that hand on her head and messed up her hair in revenge.
"Wah! Hey!" She hurriedly moved away from him and then ran both of her hands through her hair, putting it back in order before glaring at Sakuta. "I get up at six to style that, every day!"
Fashionable girls had really early mornings. He then ignored Tomoe and took a deep breath.
Panicking wouldn't help. There was no meaning in getting worked up about what had happened. If he took the situation as it was, he should naturally be able to find a solution.
"Well, whatever. I'm probably going to be repeating this anyway."
Tomoe certainly seemed to be Laplace's Demon, but he couldn't really say they had gotten to the bottom of it. Naturally, they hadn't found any methods to begin solving it, so as far as Mai went, if tomorrow… or rather the fourth today went well then all would be solved. He would just need to be careful he didn't end up holding Tomoe.
Nothing more was needed, it was a wonderful solution.
But come morning, Sakuta would regret the judgement he made here and now…