Nanashi's surname of Toriyama comes from the most famous Akira.

On a side note, since Igor pulled them each from their timelines, they don't have any relatives or history in the new worlds. So the thing at Moonlight Bridge never happened, they're not related to the Dojima family, and Sojiro does not know their parents. It might be interesting to see what kind of plot comes out from a completely unrelated protagonist, but the butterfly effect might invalidate some of my material, so I'm handwaving it all away. The Moonlight Bridge incident happened to a random first-year who doesn't have the potential to use Persona (somehow), the trio lives with the Dojima family as paid boarders, and… um… Sojiro took them in out of the kindness of his heart?

The Greatest Enemy is the One you Least Expect

The three boys could not experience the same adventure at the same time. That is, each of them experienced an alternate universe where they were the Wild Card, but for some reason they could not all be in their own separate versions of Inaba at the same time. But placing each boy in a different adventure for one year robbed them of the ability to commiserate and figure out their problems together. So Igor came up with the ingenious solution of switching off.

Rather than having each boy spend a year in every world, Igor had the three boys spend a week in each world before moving on to the next one. Kazuya would begin in Tatsumi Port Island, Naoki would start in Inaba, and Nanashi would return to Tokyo. Then Kazuya would go to Naoki's world, Naoki would go to Nanashi's world, and Nanashi would go to Kazuya's world. A week was long enough for them to gain their bearings, make plans, and distinguish between their new teammates. Igor congratulated himself on this stroke of genius, so naturally it was to his immense dismay when he realized he forgot to take time travel into account.

"Should you fall in combat, I can return an hour or two without issue," Igor had said. "But should you require anything more severe, be warned. If one of you goes back, all of you do."

Nanashi was not someone to whom shyness came naturally, so it was without any hint of shame that a mere one month in did he ask to return to the very beginning of the year.

Normally, this would have been a good time for Kazuya, who did not take usually allow other people to run his life, to protest. But he just nodded grimly and said that he needed to start over as well.

Igor didn't need to hear Naoki's response to know that he needed it, too. It was all over his face.

The three boys had sat down on some squishy armchairs that Igor had conjured up. Since the Velvet Room took the form of the users' destinies, it had morphed into a bizarre but not unpleasant mix of an old-fashioned train's dining car, the first-class section of an airplane, and a fancy horse-drawn carriage.

"So," said Nanashi. "Time travel aside, how was your month?"

Kazuya's grimace was as silent as ever, and Naoki's tattooed face, regarded by the Embryon as the most terrifying thing to ever exist and the last thing many an unfortunate demon saw, was glowing red as a cherry.

"We've all messed up, don't be shy!" said Nanashi cheerfully. "I'll start with my screwups. Okay, you know how I went to Tokyo first?"

X

"Hey, Nana!" said Ryuji, looking over Nanashi's shoulder. "What's that you got there?"

"This?" said Nanashi, neatly straightening his papers. "This is my schedule. The batting cages look interesting, so I'm going there after school. I hear good things about this restaurant in Shibuya, and I still need to fetch supplies for our next raid. They don't have arcades where I'm from, either, so I'm checking that out. I got a job at some beef bowl place, so don't worry about where our funds are going. Oh, and homework."

"Wow, looks like you got the whole week figured out!"

"Week?" repeated Nanashi.

(Apocalypse keeps track of the date, but not the time, so there's no limit on how much you can get done in one day).

X

Chie and Yosuke looked at each other uncomfortably. "So, I get that you're a city boy too, and you've never seen anything wilder than a pigeon… or maybe a bear at the zoo…" said Yosuke nervously.

"And you might be under the impression that the country is full of wild animals, and we need to protect ourselves," said Chie.

"But that deer was just being friendly," said Yosuke. "I think it wanted a treat."

"Do you… do you just carry around a carving knife wherever you go?" said Chie.

"I don't see what the problem is," said Nanashi, shifting the weight of the dead deer on his back. "Oh, it's the staining, isn't it? Don't worry, blood washes off if you know the trick."

"That's… really not the problem," said Yosuke, bile accumulating in his mouth.

"Really?" said Nanashi. "Want to split the meat? I don't think Nanako and Mr. Dojima can eat all this."

"Thanks, but… no thanks," said Chie. Yosuke had ducked away to throw up in some convenient bushes, much to Nanashi's confusion.

"You can have the head."

"I don't want the head!"

X

"Check these out!"

Yosuke drew a pair of swords from his bag, and began to wave them around as if he had never held a sword before.

"May I see them?" asked Nanashi before he could cut himself.

"Sure, here you go."

Nanashi inspected the longer one carefully, weighing it and judging its edge. "It's too heavy," he said. "It'll last you, if it's a bludgeon you need, but it can't keep an edge." He tossed one of the steaks into the air, and hit it with a downward strike. It fell onto the paper plate with a wet thud. "You see how it's not cut deeply enough? A good sword needs to make a clean cut. It's long enough for some good leverage, but I wouldn't stake my life on it."

He picked up the shorter one. "This one's nice and sharp, but the grip is—"

And then he was tackled by a burly police officer.

(Disclaimer: I am not a sword expert).

X

Tokyo had changed a lot since Nanashi last saw it. There was sun, for example. And rain; rain was just a story the old-timers talked about whenever they needed to cry together, so Nanashi didn't understand why his classmates were so upset when he splashed in puddles. The lack of demons didn't exactly come as a surprise, since it was one of the most commonly sung virtue of the Old World, but it was weird seeing only humans in the street.

Well, not just humans.

It had taken Nanashi a while to process the idea that people in this Tokyo didn't just walk everywhere. They took the train and bus, rode bikes, and sometimes drove or rode cars. Nanashi had ridden bikes before, but indoors, because demons loved chasing fast things. Some people rode demons out in the open, but Nikkari advised against it; if you encountered a demon horde, your demon can't fight with you on it, and the horde isn't going to politely allow you to dismount. Flying demons had the compounded issue of being in the open air with only other flying allies to come to your aid.

And that was why Nanashi got hit by a car on the day before he attended school. Since he was no longer undead, he suffered severe injuries that would have hospitalized him for months had Justine not been looking his way. He made a miraculous recovery and was sternly told not to do it again.

X

"You can't just keep eating junk all the time, Junpei," sighed Yukari. "Look at Nanashi! He eats his veggies!"

Junpei looked back at Nanashi blissfully scooping another spoonful of canned broccoli into his mouth. "Dude, you seriously like that?"

Nanashi did not notice. He was too busy savoring the tiny tuft of deep green drenched in pure water.

Yukari put her hands on her hips. "See? We should all follow his example!"

"I wouldn't do that if I were you," said Akihiko, looking up from a magazine. "You haven't seen the junk he eats when he goes out."

Yukari blinked. "Doesn't he always get salad whenever we have club dinners?"

"That's not what I meant." Akihiko turned to Nanashi, who had set aside the broccoli for later and moved on to his leftovers bag. "Hey, Nanashi. Are you really going to eat that?"

"I don't see the problem," said Nanashi, taking a bite out of a sandwich he found at the top of the trash.

(In SMT4 and 4A, killing demons doesn't net you cash, so your primary source of income is selling vendor trash called Relics. These Relics can be food, furniture, tech, old money, etc. and can be found in all kinds of places, including trash cans. Canned fruits and vegetables are among the most expensive Relics, only eaten on special occasions. Fresh produce comes from the Yakuza-owned farms, and the Yakuza doesn't share).

X

Nanashi had a rough day. First he missed breakfast, got shoved into an alternate dimension, and then he got chewed out for being hours late for the first day of school?

He just wanted to go home and take a nap before trying out this 'homework'.

Crowded and yet devoid of demons, Nanashi trudged down the achingly familiar path home, smiling at the shining sun above.

A few hours later, Sojiro had to pick him up from Kinshicho station, after a security guard caught him napping in a maintenance closet.

(Most people in SMT4's Tokyo live in underground shelters modified from train stations. Nanashi lives in Kinshicho station. Also, if he had Morgana in his bag, then Morgana would have pointed out that they were going the wrong way).

X

"All right, that's how your month went, but why do you want to turn back time?" asked Naoki.

X

"Would Nanashi Toriyama please report to the principal's office."

The Phantom Thieves froze.

"Seriously?" said Ryuji. "There's no effin way—"

"They can't prove a thing," Morgana assured him.

Ann nodded. "We're with you, whatever happens."

This was not the first time Nanashi had been called to meet with an authority figure, but this time no one was crying for his death.

"Mr. Toriyama," sneered the principal. His gaze flickered towards his partially shaven haircut, and he scowled even more. "Please sit down."

Nanashi remained standing.

The principal tut-tutted. "I suppose an attitude like yours shouldn't matter where you're going." He tossed a few papers in front of Nanashi. "Do you recognize those?"

"They're my old homeworks," said Nanashi.

"And five of your tests," said the principal. "Can you read the numbers in the corner?"

"Yes."

"Say them."

"Five, eleven, seven, eight—"

"My point exactly," said the principal. "Your grades, in short, are atrocious. You have not passed a single test or quiz since your arrival." He crossed his arms. "We were willing to take you in despite your… record,"(the principal somehow piled a Café Florida's worth of hatred into the word) "but you cannot keep dragging the name of our school through the filth of whence you came. You are expelled."

X

"…So, if you could tutor me until I'm all caught up, that would be great," said Nanashi.

"If you're going all the way back, we can make you a first year," said Caroline.

"But we cannot change your class in Inaba," said Theodore.

"I can tutor you when we switch off," said Naoki, standing up.

"Don't you sleep during class?" said Kazuya.

Naoki crossed his arms. "I graduated, remember? Studying now won't let me retake college entrance exams."

Kazuya blinked. "Wait, if we're just going back, what's the poi—?"

"Don't," said Nanashi, grabbing Kazuya's shoulder. "He's going back to a world where they still have libraries and the internet. You're going back to a world where nobody knows what to call big buildings filled with books. Your world needs the knowledge of this one."

Kazuya did not argue, which with him was as good as an agreement.

Naoki cocked his head. "Didn't you say you were his age when the nukes hit? How are you doing in second year?"

"Passably."

TO BE CONTINUED!

I don't think the average post-apocalyptic teenager can keep up academically with one who spends the bulk of their lives hunched over a desk. Some can, and plenty have. Just not this one.

Nanashi must be a second-year student for Persona 4 because they're only teammates because their core members were in the same class. In Persona 3, they all live in the same dorm anyways, and the Phantom Thieves met each other outside of the classroom.

I didn't have very much for Persona 3.

On a side note, the Hero of SMT1 does not have a canon age, but I think he's in high school, judging by his classmate's uniform. I gave Kazuya the age of 15 at the start because I thought the 16-17 range is overused.