Chapter Text
When Todoroki Shouto is five years old, on a Tuesday, Iida Tenya hits a picnic table. This causes a series of escalating events, which in turn leads to our young hero getting himself Isekaied into a different world--into the body of a boy named Zuko. He proceeds to get sent there every Tuesday--and similarily, Zuko is sent to possess his own body. However, we've already seen Zuko's side of things--this is Shouto's.
The first thing Shouto notices is that he's not in his house anymore. The second thing is that the inner temperature regulation of his quirk has changed, somewhat. He gets up from where he has fallen, and frowns at the fire that erupts from both hands. That's...not right. The third thing he notices is that his face feels smooth--touching it, there's no scar--and his hair is black. What happened to him?
"Zuko, honey, what's wrong?" the nice woman asks. .
"My ice is gone." Shouto tells her.
"Your ice?" the woman asked.
"Yeah. I make ice with one hand, and fire with the other. And my face feels different." Shouto explains.
"You--you...ice?" the woman asks, confused.
"I was just making ice yesterday. Then I melted it by accident. I'm still working on it, though." Shouto says. "You can't make ice here, honey. You have to keep it secret, okay? Because--that would mean you're the Avatar, and you know your Father doesn't like the Avatar." the lady says. Shouto's the confused one, now.
"The Avatar? Who's that? Father doesn't like All Might." he says. Oh! He's got it! When something strange happened, people said they'd been hit by a quirk.
"Oh, go see Azula, she's been waiting for you to get out of training." the lady tells him, and opens the door. Someone walks in--she looks about Shouto's age, and has black hair done up in a bun with a cute little fire symbol. The fire symbol really is everywhere--hey, it's on his clothes! Cool!
"What happened, Zuko?" the girl--Azula?--says.
"I got hit by a quirk." Shouto tells her.
"What's a quirk?" Azula asks, blue fire on the end of her fingertips.
"How can you not know what one is--ooh, blue fire! Your quirk is so pretty, like Touya's!" Shouto says.
"I know! It's beautiful...why'd you call my bending a quirk? Are you insulting it?" Azula asks, walking right into his face. She's a little scary, Shouto thinks.
"No! Not at all!" Shouto protests.
"Of course you're not. I'm much better at firebending than you, Zuko." Azula huffs. Firebending...that's a nice name, for a quirk. It sounds better than Father's quirk's name, at least. Shouto frown at his hands, which both flicker with flame. What happened to his ice? His special Half-Hot Half-Cold, that Touya was so jealous of, that he left. Shouto sits down. Touya had disappeared a month ago, and they hadn't seen anything of him since. He hopes Azula won't disappear, like Touya--he likes her, he thinks.
There's a tall scary guy. He reminds Shouto of Father, but worse, even. Somehow, that's possible. He's also Azula's father...and Zuko's father. Who's Zuko? People keep calling him that. Wait, did he turn into Zuko? Is that what the quirk that hit him did?
Oh...that would explain stuff. He's turned into someone called Zuko, and Azula's his sister, and this Fire Prince is Zuko's Father…and this house is so big. Is he a hero? He must be really rich--oh no! What if he's a villain?
Shouto doesn't say much, for the rest of the day. He doesn't know what to do--how to get back to Fuyumi and Natsuo--and what's happened to the real Zuko?He calms down, after a while--most quirk effects only last for a short while, it might wear off overnight. Before Shouto goes to sleep, he grabs an empty notebook, and writes in it.
Hi, Zuko! My name is Shouto, and I got turned into you, yesterday! It was nice to meet your family, and the turtleducks are so cute I've never seen a quirked animal like that! I hope you're okay.
It's the next morning, and Shouto is glad to find himself in his own bedroom. He takes a deep breath--it's nice to be home. Then, he launches himself out of bed, and runs to Fuyumi's room.
"Yumi Yumi Yumi! Guess what happened to me yesterday!" he says, jumping on her.
"Oh...Shouto? Shouto! Thank God, you're back! Natsuo, get in here!" Fuyumi shouts.
"I turned into someone named Zuko, and I met his sister Azula, and she had a quirk like Touya and their house was huge but they didn't have a TV and his Father was a lot like our Father but he was scary and it felt so strange to not have any ice!" Shouto tells his siblings, all in one breath.
"Hey, Sho. Zuko left you a note." Natsuo says, and reads a paper.
"It says: Dear Shouto, I had fun staying at your house, and I really liked watching the hero fights on TV. Your sister is a lot nicer than mine. Are you half Spirit, since you can make ice and fire? I hope I can meet you one day!" Shouto tells Natsuo he left Zuko a note, too.
"Well. That was interesting, to say the least. Oh--you didn't realize, Shouto? I think Zuko lives in a different world!" Fuyumi says.
"A different world?" Shouto asks, excitedly remembering all the fantasy stories he'd read when he was younger.
"It appears so." Natsuo says. The two tell him what Zuko said: about the four forms of bending, the Fire Nation, and the Hundred Years War.
"Wait, he's a Prince?" Shouto asks. That's so cool!
The next Tuesday, Shouto wakes to a red ceiling. He blinks two unmarred eyes that aren't his own.
"Huh." Shouto says. After hanging out with Azula a bit, it turns out that Princes of the Fire Nation have daily training and education to learn how to be a proper heir. When it comes to firebending training, Shouto is scared...he always hated training with his Father. Luckily, Ozai doesn't train them personally, most of the time--they have tutors. Who aren't much better than Father, Shouto soon realizes--especially considering that he's having trouble with the katas and forms. He doesn't know any of this!
"You're not doing so well, Zuzu." Azula says.
"You're a Zuzu." Shouto remarks.
"Excuse me?" Azula asks, scandalized.
"Zuzu is short for Zuko, but it could also be short for Azula." Shouto points out. This makes Azula sneer at him--she shows off a perfect Third Dragon form, kicking into the air--a wave of fire erupts from her hands, blue at the edges.
"Bet you can't make that much fire at once!" she says. Shouto blinks--he makes more than that on the regular. He guesses his quirk must be more powerful then firebending; ignoring the protests of the tutors, he gives up on Third Dragon and shifts into his preferred battle stance--calling on his nonexistent quirk, he easily gestures a massive sheet of fire into existence.
"How--? You only used one hand! That's not fair!" Azula complains. Shouto's not used to fire, from his right side-only sparks emit from his hand. He watches as Azula tries to replicate his feat with a single hand, and only manages less fire than him.
At night, he grabs the notebook. There's something written in it.
Shouto, if you come back, can you beat Azula with firebending? She's so much better than me, it's unfair!
Shouto smiles.
Already done!
"So, it happened again." Fuyumi says. On a Tuesday, too. She looks at the calendar, and marks it.
"Just in case." she says, ad begins thinking of ways to hide Zuko from Enji. It's working so far--she doesn't want the idea of another world getting out, that only Shouto has access to. That Zuko, who comes by, will be trapped, and her brother with him. She won't risk it.
The third time it happens, Fuyumi hands Shouto a notebook.
"So you can write to each other." she says. He draws a Fire Nation symbol on the cover.
Far away, Zuko sews red and white fabric in a circle. Lu Ten got him this notebook, and he's glad it's being put to a good use. Speaking of Lu Ten; he comes by, on the fifth Tuesday. Shouto, naturally, has no idea who he is, but has been thankfully informed that "his cousin Lu Ten is here."
"Hi, Lu Ten." Shouto says, wondering if he's nice like Azula, or mean like the Firelord.
"Zuko! Little cousin! And Azula! It's so nice to see you again!" Lu Ten says, and hugs them both.
"Why'd you come today?" Azula asks.
"No reason." Lu Ten replies.
"Cause, it's a Tuesday. Zuko's weird on Tuesdays." Azula sniffs. Shouto whirls to her. She's noticed?
"Zuko?" Lu Ten asks. He stares into Shouto's eyes.
Lu Ten knows people. His father is Iroh, the Dragon of the West, after all; he knows how to manuever through a conversation, how to treat any social occasion like a battlefield, and how to recognize the many microexpressions of people's faces. And one thing he is sure of; Zuko, or whoever is standing before him (because that is not Zuko, it couldn't be) has never seen Lu Ten before. Weird on Tuesdays, huh?
Later, he and not-Zuko are alone.
"Who are you?" Lu Ten asks.
"Er...what do you mean?" not-Zuko mumbles. He seems young, but Lu Ten doesn't know, with Spirits, for what else could it be?
"I understand you've been possessing Zuko on Tuesdays?" Lu Ten asks, outwardly calm but inside, screaming. His cousin's in danger! The Spirit bursts into tears.
"I'm sorry! I don't know how to stop! It just keeps happening!" the boy cries and whoa, he did not expect this.
"Can you...explain?" Lu Ten asks, and the boy does.
Another world. Hoo boy. He did NOT expect this.
"Okay. Shouto? It's okay. I won't tell anyone. I'll keep you safe." Lu Ten says, because he knows that Ozai is not the nicest man. If he found out--Lu Ten wants to take over the Earth Kingdom, and they're going to start a seige of Ba Sing Se soon enough, but some part of him doesn't want to place a whole other planet at the Fire Nation's mercy. They seem to being doing well enough on their own, and the Earth Kingdom's enough, he thinks. Besides, all this quirk stuff...fire AND ice. He shudders. Not to mention what Ozai would do to Zuko.
Lu Ten doesn't tell anyone, not even his father; it's not his secret to tell. He keeps it, even years later, as he marches to Ba Sing Se; he never returns.
Zuko has a knife. "Never give up a fight." Sounds like something Shouto would say, he thinks; Shouto is very stubborn, and has something against his father. Which is stupid; as far as Zuko's concerned, Endeavor's just trying to train him to be the best hero possible. And at least Shouto actually knows where his mother is, even she's gone. It's not fair! Mother's gone, Lu Ten's gone, and Azula's not the same. She hit Shouto with low-voltage lightning, last Tuesday--he hadn't even done anything, she just wanted to show him she could do it. Zuko's side still ached, and there was a slight scar.
When Shouto wakes up on Tuesday, he flips through the notebook under the pillow, as usual. The page is stained with tears.
Lu Ten passed away.
The words are scrawled ferociously, messily--out of necessity. Nothing else is written, and Shouto feels his heat fall apart--the only one who knew him, on this side. The only person who was nice to Zuko, in his broken world. First his mother, then Touya, then Zuko's mother; then Azula (even though she was right there!) and now, Lu Ten. Why did everyone leave? Why were they alone, with only each other?
When Shouto came home, Fuyumi decided that that was the final straw. She could no longer ignore her family's similarities to Zuko's.
"Come on, Natsuo. We're moving out, and I'm going to get Mom out of the hospital. Zuko needs a safe place, when he comes here; a family that doesn't remind him of where he's stuck. I only wish I could save Azula, too."