"So… it was destined that I'd come to this era?"
"More or less. Whatever you do here is part of an already determined history," Isaac said. "So you don't need to worry about changing the future. Since you're here, you're already part of this time."
"…"
Though Isaac told him not to worry, Rinji couldn't help feeling a little down.
If he could move freely between times, couldn't he save his uncle Amano?
But no matter what he tried, Amano's death would always remain unavoidable.
"Dad…"
"Hmm?"
"No matter how hard I try, does that mean I can't save people who die in the future?"
"Of course not."
Isaac said it as if it were the most obvious thing.
"Once a person is dead, they're dead. No method can bring them back. Life only happens once."
"I see… so it was decided from the beginning."
Seeing Rinji so dispirited, Isaac smiled faintly, walked over, and patted his head.
"Don't think too much about it. Even if the outcome is fixed, there are countless paths leading to it. Life is about enjoying the path to the result."
He paused, then added,
"And besides, determinism isn't necessarily correct."
"Hm?"
"There are plenty of theories that argue against it. For example, 'Schrödinger's cat' represents the uncertainty of the future. And in 1992, Hawking proposed the chronology protection principle."
The principle of chronology protection said that time itself had a self-defense mechanism, that nature rejected things like time machines or time travelers.
Time travel would bring enormous disaster, because it meant matter and information would suddenly appear from nothing, as if a complete program suddenly had an extra character that might crash the whole system.
As a programmer, the first instinct would not be to rewrite everything, but to locate and delete that extra character—or prevent it from appearing in the first place.
"The fact that you exist at this point in history means the principle doesn't apply to you. Your existence has already been permitted by nature, or maybe you've transcended it. So you can forget all the theories I just mentioned. In the end, theory is just theory. The truth depends on what you actually do."
"So…"
"Just do what you want to do. Don't worry about the future," Isaac said with a smile. "Even if the future really does change, fate is on your side."
---
"Huh? It's you, Takamine."
"Mei? You came to visit Misaki?"
"Yes."
Rinji was carrying a small gift box to the hospital to visit Fujioka Misaki when he ran into Mei in the hallway.
"Do you visit her often?"
"No, I came secretly." Mei shook her head. "My mother… doesn't want me to see her."
"…I'd better not ask about your family."
As they talked, they walked together to Misaki's hospital room.
Opening the door, they found Misaki lying on the bed, reading a book.
When she saw them, her face lit up with surprise and joy.
"Rinji, Mei, you came!"
"Yeah, it's been a long time since I visited you." Rinji placed the gift box by Misaki's bed. "How's your health now?"
"Thank you, I'm very healthy."
After saying that, Misaki suddenly puffed out her cheeks.
"Rinji, how long has it been since you came to see me? You're so cold."
"Because of some personal reasons."
Rinji smiled, then pointed at Mei beside him.
"She hasn't been coming either, has she?"
"Mei… that couldn't be helped."
Seeing Misaki's sudden gloom, Rinji figured there was definitely some story between the two, but he wasn't interested enough to ask.
"Speaking of which…"
Misaki on the bed looked at Rinji, then at Mei.
"Why did you two suddenly come together?"
"We happened to run into each other."
"I heard from your friend, Rinji, that you're also attending Yomiyama North Middle now."
"My friend? Oh… you mean him."
Rinji remembered that when he wasn't around, Isaac often came to visit Misaki in his place. Even though Isaac always insisted he was Rinji's father, it was obvious Misaki didn't believe him. It didn't make sense.
"I am indeed going to Yomiyama North Middle now. I'm in Class 3-3."
"Class 3-3? Isn't that the same as Mei?"
"Yeah."
"That's quite a coincidence." Misaki smiled happily. "Since Rinji has decided to stay in Yomiyama, that means in the future I can…"
"Don't think too much. My time in Yomiyama won't be long."
"Eh…"
---
"Misaki seems very dependent on you."
Leaving the hospital, Mei smiled at Rinji beside her. When she was with him, this girl who usually avoided showing much emotion clearly smiled more.
"I can tell," Rinji said. "It's not a good thing."
"I can see it too. Besides her dependence, Misaki even has…"
"I didn't notice that, and even if I did, it's best to stop it early."
Rinji sighed.
"I'll leave sooner or later. This isn't where I belong. Once everything is resolved, I should be looking for a way back home."
"I suppose so. Rinji, you've always felt out of place with those around you."
Mei herself had long been apart from the class. Even without being the 'nonexistent person,' she was usually alone with no true friends. Rinji's situation seemed even worse than hers.
"I've repeated this many times. I don't plan to interact much with this class. I don't even want to get along with them."
"But you still do everything you can to protect them, don't you?"