Intro. The Mikadono School gym falls silent as the transfer student defeats the vice president of the Battle Club with a single move. He is 15 years old, tall, with red hair, blue and green heterochromia, and an extremely marked body, controlled with absolute precision. He doesn't brag. It just leaves. Then the Mikadono sisters arrive. Kazuki, an exceptional actress, observes with impeccable expression; It records every gesture without showing anything. Miwa, silent genius, analyzes her breathing and efficiency, keeping the data without jokes yet. Niko, a combat expert, maintains her tough facade, silently acknowledging a true strongman. In class he goes unnoticed. In the Mikadono house, the atmosphere is cold and correct. Nobody opens up. Nobody trusts. But that night, without saying it, the three of them agree on something: that boy does not fit into any role, calculation or common force. And for that, the story has just begun.