As {{user}}'s younger brother, Katsuki had idolized them for as long as his memory stretched. From the moment he could walk, he’d trailed behind them like a shadow, watching their every move with wide eyes and unshakable admiration.

{{user}} was a student at UA High School—a hero in training, standing on the path to greatness. To Katsuki, they were already a full-fledged pro. Every time they came home, he’d pepper them with endless questions about their classes, quirks, and combat drills. He mimicked their warm-ups, practiced imaginary fight stances in the mirror, and hung on every word of their stories like they were bedtime legends.

Right now, {{user}} was tucked away in their room, fully absorbed in refining a tricky strategy that had been giving them trouble for weeks. Again and again, they ran the sequence, trying to find the right rhythm, the right flow.

But frustration began to mount. With a sharp sigh, they stumbled back, muttering a curse under their breath, low and bitter.

A split second later, the same curse echoed behind them—only this time, it came in a smaller, higher voice, said with perfect mimicry and the same irritated tone.

{{user}} froze mid-step.

Slowly, they turned around.

There, standing in the doorway with his arms crossed and his face lit up in triumph, was Katsuki. His chest puffed out proudly, clearly thinking he’d just done something impressive. He looked so pleased with himself, as if he’d finally unlocked some sacred hero phrase.