Months had passed since the chaos of their early days in school, and Gray found himself settling into a quiet rhythm, at least as quiet as life could be with Natsu as his brother. Gray knew he had to keep away from trouble. Getting kicked out of school was not an option if they wanted to become heroes someday. Although he still didn't know why he wanted to be a Hero. For now, he didn't want to be restricted. But was that it?
In the classroom, Natsu still struggled more than anyone else to stay still. His restless energy was a constant challenge, and Gray often caught himself glancing over to make sure Natsu wasn't about to burst into another fight or tantrum. Despite the trouble, Natsu passed his classes by relying on basics, and his stubborn confidence. "Math is universal, damn it," Natsu had once declared, barely suppressing a grin as he scribbled through a problem.
"You idiot flamehead, this is school for kids, you shouldn't be struggling…" Gray sighed.
Gray, on the other hand, breezed through the lessons. Being an adult in a child's body gave him an edge. He quietly excelled without drawing much attention. It was easier for him to focus, but the lingering question still haunted him, what exactly did he want to do as a hero? He wasn't sure yet. Unlike Natsu, who had a crystal clear goal: "I want to fight All Might and Endeavor one day." The fire in Natsu's eyes was unmistakable. At least it was a plan. He felt somewhat envious of Natsu having such a clear goal.
Gray had no grand plan. "I'm just going with the flow for now." he had told Natsu one afternoon during a rare break between classes.
Instead of wasting energy on uncertainty, Gray decided the best course was simple: train. Pour everything he had into mastering his quirk and body. Natsu agreed. Training was the way to conserve energy and control their explosive power. Still, mild chaos followed them wherever they went, small fights, pranks, and the occasional scolding from teachers.
Their triplet brother, Shoto, was quieter. Gray and Natsu made it a point to spend time with him whenever they could, even if Endeavor's strict training schedule often kept Shoto busy. Endeavor remained oblivious to the true potential Natsu and Gray held back. Their full strength only showed in secret sparring matches between the two brothers, moments when they stopped holding back, and raw power surfaced. Otherwise, they stayed under the radar. They weren't even actively trying to be secretive. Their father just never paid any attention to them.
During a practice session, Gray noticed something alarming. He found that overusing his quirk came with consequences. His body started freezing, growing numb and stiff, and the intricate ice techniques from his previous life eluded him. Complex "Ice Make" shapes were difficult to replicate in this new world. All he could do was release a burst of ice out of his body. He wasn't expecting it to be that different. But, he was wrong.
He concentrated, trying to create at least a basic sword, but it was massive, crude and unwieldy. It looked more like an ice slab. He had Natsu melt away the ice to try again. However, it was still the same. Quirk's weren't magical in nature, they were like muscles. He had to keep training. He also needed to extend how much ice he could produce. He thought back to his teacher Ur's old training method.Maybe going somewhere cold to train would prepare this new body to get used to it.
One day, he resolved, he'd find a colder place, maybe a mountain or an ice cave, and attempt to train under harsher conditions, just like his old teachers did. For now, he focused on steady improvement.
Natsu's challenges were surprisingly similar to Grays. Instead of overheating, he grew exhausted and cold and needed to consume fire regularly to keep going. The flame was his lifeblood. He trained to improve his input and output, to control how much fire he needed and how efficiently he burned it. There was no overheating as long as he had a steady supply of fire, but managing stamina was crucial. For now, it was back to training.
A couple hours of recovery later. Gray called Natsu back for a quick sparring session.
"Oyy Natsu, let's do another quick sparring session using quirks. Natsu nodded and ran forward to the yard. They both stood 10 meters away from each other.
The training yard was quiet except for the sound of their heavy breaths and the crunch of frost underfoot. Gray stood tensely, fingers already chilled, ready to use his ice quirk.
Natsu cracked his knuckles, flames flickering lazily from his palms. "Let's get this over with."
Gray didn't reply. He swung his arm forward, sending a wave of ice rushing toward Natsu. It wasn't pretty, just a rough wall of frozen ground and shards, nothing intricate.
Natsu grinned, dodging easily. "Man, your ice's still basic. Like Shoto's."
Gray frowned, rubbing the back of his neck. "It's hard. This isn't magic, quirks don't work like that. Making fancy stuff? Way tougher than it looks."
Natsu snorted, flames licking at his feet. "Yeah, same here. I just light my feet and hands mostly. Nothing fancy."
Gray narrowed his eyes, pushing frost up from the ground to trip Natsu. The flames flared up, melting the ice before it could reach him.
"Your ice's pretty strong, though," Natsu admitted as he lunged forward, flames flaring around his fists.
Gray blocked clumsily, the heat burning through his makeshift ice shield. "I'm still figuring it out. If I overuse it, I freeze up."
Natsu wiped sweat from his brow. "I get tired. Gotta eat fire to keep going."
They circled, neither giving ground. The fight was rough, chaotic, full of crashes and sparks, but neither could hide their respect beneath the smirks and jabs.
When they finally slowed, panting in the cooling air, Natsu flicked a small flame onto Gray's shoulder.
"Next time, bring something better than ice walls," he teased.
Gray just shook his head, a faint smile tugging at his lips. "One day. I am still too weak."
If Endeavor had been watching and heard what Gray said, the fire hero would have frozen in place. These two six year olds, barely even tall enough to reach their knees, wielded their quirks with a control and ferocity that defied their age, and apparently, it wasn't enough for them.
Natsu stumbled back, flames flickering weakly around his feet. For once, the usual fire in his eyes was dimmed by exhaustion. "Alright… I'm done for today," he admitted, voice rough. "Need some fire quick or I'm gonna pass out."
Natsu gave a tired grunt and pulled a small, well worn lighter from his pocket. "Emergency stash," he muttered, flicking it open and sparking a tiny flame. Without hesitation, he leaned forward and inhaled, drawing the fire into his mouth. The heat flared briefly inside him, fueling and warming his body.
Gray watched quietly, frost still creeping on his arms. "You really carry that around? I thought you could go days without fire now?"
Natsu grumbled, "Yeah, that's only if I am not using my quirk. When I use my quirk, I feel like I'm draining myself faster. That's why I gotta work on being able to use my quirk for extended periods without shutting down."
He closed the lighter and pocketed it, the fire inside him reigniting his energy just enough to keep going, at least for a little while longer. The lighter was specially made as well to fit Natsu's diet. The flames were powerful. One good thing about being the number 2 hero's son.
Gray, already shivering slightly, wiped frost off his arms and legs. His breath came out in a soft puff of white mist. He didn't argue. "Yeah, me too," he groaned, rubbing his numb fingers. He then placed both his palms in front of Natsu.
Natsu knew what he was asking for and rolled his eyes. "Ugh… I am not your personal heater, you know?"
Gray shot him a tired glance. "Don't have a choice, do I?"
Grumbling but obliging, Natsu drew a small flame into his palm, eyes burning just enough to warm them both. "Here."
Gray held out his icy hands cautiously toward Natsu's flame, feeling the heat slowly chase away the creeping frost.
They had been here for 6 years. Clearly, it wasn't just an illusion or some supreme magic in place. Perhaps there was a small part of Gray's mind that had hoped for something, but every day, that grew less and less. However, he was happy with his new life. It had its challenges (mostly endeavor) but it was nice. He looked at Natsu for a moment and sighed. At least he still had Natsu with him. Of course, he would never say it out loud.
For a moment, neither spoke. Just the faint crackle of fire and the cold settling between them. A truce after sparring.
-
Two years passed like a steady tide, not slow, not fast, but unrelenting. The Todoroki household shifted in small ways during that time. Rei was doing well in her therapy and was allowed to interact more and more with the family. She was even allowed to spend more time with the kids. She returned to being calm and gentle as she was, always with warm hands and tired eyes that softened whenever the boys were nearby. Fuyumi was still bright and bubbly, keeping track of the boys and making sure to help out around the house. Shoto… Well, he was still enduring the heavy hand of Endeavor's training, but now and then, he'd find time to sit beside his brothers and just breathe.
And the triplets Natsu, Gray, and Shoto grew.
At eight years old, Shoto was a model student. Brilliant, quiet, composed. Gray was nearly the same, excelling in school with an ease thanks to his true mental age. Natsu, on the other hand, was… passing. Just enough to scrape by. He was terrible at sitting still, often fidgeting during class, tapping his pencil against the desk until it drove teachers insane. But when it came to physical education? No one came close. His speed, his reflexes, his bursts of strength, they put even older kids to shame.
Even so, Natsu and Gray didn't let grades or classroom labels define them. Their focus was on something else entirely.
Training.
Their mornings started early, often before the sun even touched the rooftops of Musutafu. They trained in the extra empty rooms in the house. Endeavors training was mostly focused on Shoto, and his hero work. He wanted to teach Shoto all of his fire techniques. He didn't believe the ice was for anything except regulating his temperature for when he overheated. He didn't want to teach Gray since he had his mothers Ice Quirk. He asked Natsu if he wanted to join Shoto. Natsu looked at him like he was an idiot and ran off. After that he gave up asking him. Between this and his Hero work, he didn't have any idea what Natsu and Gray were up to. The house now only had a single cook and Endeavor's driver. They didn't need the extra servants anymore.
Their sessions were brutal.
Gray crouched low in the yard, frost trailing from his palms, eyes locked on Natsu. He'd learned to temper his quirk better now. Ice shot across the grass in jagged waves as he extended his hand, the cold snapping audibly in the morning air.
Natsu vaulted over the attack with a burst of fire from his soles, spinning midair. "Too slow!" he shouted, flames flickering around his fists. He launched toward Gray, a blur of fire.
Gray twisted his body, dropping low and slamming his palm to the ground, freezing the area under Natsu's landing spot. Natsu landed with a grunt, slipped, and tumbled into a nearby bush.
"Damn it!" he groaned, half muffled by leaves.
Gray smirked, walking over. "You said you could go sideways now."
"I can!" Natsu shot up, brushing himself off. "I just need to control the angle and strength better."
He flicked open a small silver lighter from his pocket, thumbed the flame up, and devoured it in one motion. His shoulders relaxed immediately, slowly recovering.
"You sure you're not just my portable heater?" Gray muttered as he exhaled, a visible puff of cold air. Frost was already crusting along his arms and legs.
"Not your heater," Natsu grumbled, but still moved closer and radiated heat for him anyway.
Gray groaned softly. "Ugh… that's better. It's been a while since I felt cold. I hate it."
During the winter months, their training became even more intense. Gray began replicating a method he remembered from his old life, standing shirtless in the snow, using the environment to both challenge and strengthen his endurance. He'd spend countless hours outside, calling forth his ice, forcing it to move, shape, twist even when the wind bit at his skin. His life consisted of School, some social activities with his siblings, training and sleep. He didn't really care about going out too much. He just wanted to keep seeing how far he could go with his quirk.
His control had improved. He still couldn't replicate his old Ice Make magic, not with the intricacy he once knew, but he could manage crude shapes, spikes, sheets, crude swords and barriers. But Gray was disheartened. He just chipped along with it slowly. There was no rush, he had plenty of time to train.
And Natsu trained right alongside him.
Winter was harder on Natsu. He tired faster, his flames burning less intensely. But it didn't stop him. He practiced his breath attacks now, managing short range fire bursts. He called them "Fire Roar," They weren't worthy of being called a fire dragon's roar.
One evening, during their sparse family time, the triplets sat together in the living room. The news was on in the background.
Fuyumi sat on the floor, humming softly as she knit something, a scarf maybe, or a sweater, no one was really sure. Gray lounged back against the couch, arms resting limply, still chilled from that morning's cold weather training. Rei made sure to keep an eye on him when he kept coming back with frost on him. She tried to get rid of his stripping habit but there was just no way. She just left it as it is and hoped he would just grow out of it. "Haise, please stop going out in the winter without clothes. I don't want you to get sick."
"I don't technically go out without my clothes," Gray replied.
Natsu, sprawled out like a cat by the heater, lazily replied.
"Yeah, he just strips when he's out there."
Shoto laughed. "Bro, you gotta stop striping or you will get arrested.
Gray just grumbled.
The TV blared with the news of Endeavor's capture of the villain.
Natsu slightly looked up when Endeavor appeared on the screen. They all watched silently as the hero darted across buildings, molten handprints steaming behind him as he propelled himself with carefully placed flame bursts.
Natsu blinked. He widened his eyes in surprise the next moment. He realized something he could try.
"…Huh."
The next day, he tried it. Fire burst from his feet, from his side, even from his back.
Then he crashed into a wall.
Twice.
Gray, who was passing by, holding a mug of juice, noticed the disturbance in the room. He walked in to find a Natsu lying on the ground, his face red like he slammed into something.
He walked over to Natsu and gave him a quick glance. He took a slow sip out of the mug and stared intently at Natsu and the Wall next to him which looked like someone slammed their head into.
"What happened, did you finally go crazy?"
"Training…" Natsu groaned as he rubbed his face.
Gray didn't press, and continued drinking. But Natsu explained it anyway, excitement bleeding into his tone.
"He was melting the buildings and making footholds, and propelling using bursts right? So I figured I could just use fire bursts at different angles! Sideways! Diagonal! Up! Down!"
"And the wall?"
"I missed."
"Repeatedly hitting the same wall?" Gray questioned.
Natsu just rolled his eyes.
Later that week, Natsu attempted the move during another training session in the yard. Gray was watching from the side. He decided to just rest for the day instead of training. After all rest was just as important. He didn't want to overwork himself. He sat down and watched Natsu repeatedly roll around as he practiced his new technique. It was better than any TV he watched.
Natsu burst forward, then immediately tried to charge to his right. Making a complete right turn. The move looked like it was almost working, however, he overshot and burst into the shed, bonking himself head first.
As he lay groaning in the grass, Gray sat beside him, breathing hard, a thin sheen of frost covering his shoulders.
Then, a shadow loomed. Endeavor stepped into view, arms crossed, brows knit.
He said nothing. Just looked down at the boys. One collapsed, the other calmly sipping a juice box.
He sighed heavily and walked away.
The two brothers exchanged a glance.
"That was weird, right?" Gray muttered.
"Yeah. What the heck." Natsu agreed.
Their training continued to evolve. Gray worked on a movement technique of his own. At first, he tried skating on ice trails, but it proved too slippery, too chaotic. So he adapted, forming ice plates over his legs, holding him in place, giving himself grip and friction while still riding the momentum of his quirk. His speed improved. His stamina grew.
By the time they turned eight, they could spar for nearly twenty minutes without needing a break. Natsu could control the temperature and intensity of his flames to a fine degree. His mobility quirk, while still raw, was becoming viable. Gray could freeze entire portions of the yard with a single sweep if he wanted to; however, he kept his ice practical and efficient. There was no point in freezing everything around unless he had to.
Yet, despite all their growth, their chaos never quite disappeared. One time, Natsu melted a fence post trying to hover. Another time, Gray accidentally flash froze Fuyumi's laundry, while trying to make something.
"HAISE TODOROKI!" she yelled.
"…Oops."
But in the end, they were growing. Stronger. Sharper. Better.
Although Endeavor watched them a few times practicing. He never figured out what they were truly capable of. And most of their sparring devolved into slugging each other until Rei or Fuyumi broke them apart.
He left them to their devices. After all, he didn't care if they wanted to be heroes. If they did, that was fine. He just needed to train Shoto to finally surpass All Might.
However, he didn't realize yet how strong they already were at just 8 years of age.