The first time Izuku met Nezuko Kamado was when he was seven years old. She wore what she was always wearing, traditional clothes from an era long past. She looked young, certainly younger than his mother, and the small pink bow in her hair that mirrored the color of her eyes made him wonder why someone at that age would be living alone.

She gave him a smile filled with teeth that caused him to hide behind his mother, who had greeted the woman with a bright smile of her own.

She had the entire house next to them for herself. Nobody else came in or out. Sometimes, around 6AM, when he was restless from the images of heroism in his mind and woke up early to watch a few more All Might clips, he could hear strange sounds coming from her home.

The sounds of flowing water and a burning sunrise on Mt. Fuji.

He always wanted to ask her, but he couldn't work up the courage. She looked nice, but his mother always said that asking personal questions was rude. So Izuku watched from afar, taking notes whenever he could discern something new.

It was five years later when he would find his answer.

She spoke in an old-fashioned way. A mix of what would count as modern and what one heard in the old samurai dramas that his mother never let him watch. It fit her.

And it was something he would get very familiar with soon enough.

"I don't get why I can't come with you," Izuku, aged twelve, muttered into the nape of his mother's neck. Her hugs were as tight as always, and yet he didn't want to let her go.

"You have school, Izuku," his mother reminded him for the twenty-fourth time. "It's only a week, too, I'll be back before you know it. Kamado-san will take care of you until next week. And if anything comes up, you can call me, right?"

His mother, always kind, was unwilling to tell him the reason for her trip but Izuku was not as gullible as she thought he was. He understood that the reason for her tight-lipped behavior was that she thought he couldn't take the truth, and yet she remained unwilling to lie.

And as he wasn't gullible and as kind as his mother, he couldn't make himself ask for a proper answer. She let go of him and he sucked a deep breath, forcing himself to smile at her as she took her bag and sat down in the taxi.

He waved her goodbye as Nezuko Kamado-san stepped up to him. She didn't put a hand on his shoulder, but the way his eyes pierced into him was something he had no trouble feeling. He sniffed, trying to keep the stinging in his eyes out by rubbing them. It helped little, crying as for the first time in twelve years he was alone.

Or perhaps not quite alone.

Nezuko bent down, taking his free hand. He didn't feel up to shrugging her off, letting her lead him to her house.

"Welcome," she eventually said, her voice low like she was talking to a startled animal. Or maybe, a voice that wasn't used to talking to people in general.

He remembered many times she only gave his mother one word answers, often so low he could not hear.

"Thank you," he mumbled in a voice even lower than hers. She didn't seem to have any troubles hearing him, though, instead giving him a small smile. "I apologize for the inconvenience."

"I volunteered," Nezuko said. "Your mother needed help."

She did. There was some bad blood between her and Auntie Mitsuki, due to the rough treatment that he had endured in school from Kacchan. Though the abrasive mother was not unwilling to accept that her son was a bully, the lack of subsequent reining in had caused sort of a falling out.

At least that was his mother's interpretations of the events. Bakugou hadn't even done as much as look into his direction since then, but that didn't stop the rest of the class from mocking him.

"Don't you have work to do?" Izuku asked. She shook her head. "I'll stay out of your way if you do, it's the least-"

She put a finger in his mouth, causing him to grow red around the ears. Less distracted by his circumstances, he looked around and saw the same thing he always saw when he came home. The rather simple hallway with stairs that led up, though the living room looked like it had been prepared as a second bedroom instead, the couch moved aside for a futon.

Izuku minded his tongue afterwards. It was Friday evening, which meant that there was no school tomorrow, which left him with nothing to do. He watched TV until it was time for dinner, and went to bed early that night.

It was dancing. Though she had a sword in hand, Izuku could not describe it as anything but dancing. At 6AM on the dot he was out and about, walking up the stairs of the house to be met not with a hall but a dojo. The windows were letting sunlight in, tinted from the outside so one could not see what was happening, but today he solved the mystery.

Nezuko's body moved with the grace and force of a flowing river, and at the tip of her sword there was water. Though her clothes seemed inadequate for the movements, she was hampered not one bit.

He had found his breath running out as he watched. As he tried to mirror that strange rhythm that she had set.

It was only when she noticed his approach that she stopped, her dance halting in a single motion and the sword's otherworldly glow vanished. She turned towards him, blinking. He released the breath he was holding. He coughed slightly.

"Is that your quirk?" he asked, unable to keep the awe from his voice. The sense of wonder that his mother had asked him to never lose. "It's… pretty."

He stumbled over his words, realizing that he had taken a few steps forward without noticing. She smiled, turning around to put the katana back into its sheath and onto the display where it hung under two papers that looked like hanafuda playing cards.

"Good morning," she eventually said. Izuku blinked back at her, his face rising to meet her eyes as she stepped up to him. "Did I wake you up?"

"No," Izuku said, shaking his head slowly. "I always wake up early."

It wasn't the entire truth, but she wasn't the reason he woke up. The unfamiliar ceiling, the unfamiliar bed, the fact that his mother was not in town. These things added up, he had troubles falling asleep, and he kept waking up repeatedly until he heard the sounds of the dance.

"I'll make some breakfast then," she said, taking his hand and leading him back down. He turned around as they walked towards the stairs, his eyes once more fixed on the katana.

"You want to ask me something," she said suddenly as they were eating. Izuku, who had previously only nibbled on the pieces of fish that she had prepared, swallowing the thing whole as if it would distract from her question. "It's fine."

"You're… not mad?" Izuku asked. His mom always told him to respect other people's privacy, so sneaking up to her dojo, for a lack of better word, felt in violation of that respect and trust. Nezuko shook her head, giving him the courage to ask. "Those sounds I kept hearing all the time, that was you practicing, right?"

"You heard them?" she asked. He tilted his head, confused at the question. "I suppose that's not impossible, but the walls are supposed to prevent that. Hmmm."

She put her chopsticks down, her plate already empty. Izuku noted that the meat she had eaten was perhaps more than a bit on the rarer side that he liked. He simply nodded in response to her question, waiting for a follow up.

"If I tell you this secret, you have to promise not to tell anyone else," Nezuko said. Soft-spoken as always, but with an edge threatening to come down and cut out his tongue if he broke such a promise. "Not even your mother."

"I promise," Izuku said. Nezuko appraised him, as if her cat-like eyes could see the honesty in his words from the way he sat. After a moment, she nodded.

"I am quirkless," she said. Izuku blinked. The silent question must have been visible in his eyes, and she nodded. "What you've seen was not a quirk, it was a style of sword fighting that my brother had taught me."

He would argue that something like that seemed ridiculous, but in a world of superpowers it was hard to find fault in the idea.

"And I'm not twenty years old," Nezuko continued unabashed, her fanged grin once more visible, gleaming in a way that made Izuku flinch. "I'm… not sure how old I am now, but back in the day, long before quirks appeared, these techniques were used to hunt demons."

Izuku swallowed. The implication of what she was saying hung in the air and came crashing down on him with a vengeance. He all but fell out of his chair, standing up quickly to assure his babysitter slash neighborhood demon that he was alright.

"D-demons?" he asked, biting his tongue. "L-like monsters? Who eat naughty children?"

"They didn't really discriminate between the bad and the good," Nezuko admitted. She stood up, grabbing the empty plates and taking them to the sink. Pulling up her sleeves, she began washing them, leaving Izuku to his thoughts.

"T-the sword techniques, if they're not a quirk," Izuku said, swallowing a lump in his throat. "Can anyone learn them?"

"I would not say anyone," Nezuko said, shaking her head. "There are people who have a certain disposition towards other styles, I know the basics of most of them but they were never made for me. The only one I have mastered is the one my brother had taught me, the one that he had learned from his master."

"How do you know which fits you?"

"I don't know," she said, smiling at him before turning back to the dishes. "It's a matter of trial and error. You need to train your body and your spirit, it's a very arduous process. Even more arduous for me, as I am not a human."

"Demons have trouble learning?" he asked, blinking. She nodded.

"Imagine what a human can do in ten years," Nezuko said, putting the now clean plates to the side to dry. "Learn any skill, whether you try to become an artist or a mason, ten years and you will be better at it. A demon, whose age is nothing but a number, they have too much time at their hands. What a human learns in a year, a demon learns in ten. What my brother learned in five years took me fifty."

It was still difficult to see her as anything but the college-aged girl next door, but the way she spoke and dressed, even the things she said, they all pointed towards the one truth. This woman was old. Old and wise.

"Can you teach me?" he asked. Almost begged. She furrowed her eyebrows, stepping around the table. "I… I want to be a hero, but someone like me without a quirk, I'm just useless-"

Her hand came up to his hair. He flinched slightly, taking note of the rather talon-like fingernails that passed near his face before her fingers began to rub his hair. She pressed down slightly, in a way that was not uncomfortable at all. Rather, it had the opposite effect, and he found himself leaning into his neighbor's touch and the comfort it brought.

"I learned this not to master it," Nezuko said. "But to pass it on. If you want to learn, I will teach you. But you must know that it will not be easy. I'm not as good a teacher as my brother was."

"I'll work hard," he said, both in promise to her and to himself. He bowed, thankful, and looked up again to find her smiling brightly. "S-sensei! Thank you."

"There's no need to thank me, this is my selfish desire to pass on what I have learned," she said, her smile brighter and more passionate than before. "You have something to protect, do you not?"

Preview, Chapter 2: The Entrance Exam

Izuku winced as the small needle pricked his earlobe. "Are you sure, sensei?"

She held one of the hanafuda earrings up, attaching it to the freshly minted hole. She nodded, repeating the motion with the other ear and put her hand on his head, rubbing his hair.

"There's no one else who would wear them as you do, Izuku-kun."