A girl searching for a stranger's scar on his back, hoping he's the one who saved her. That's the entire romance engine, and it works because her obsession isn't cute, it's real. She trains in judo to become worthy of him, then walks into a school where multiple boys carry that same mark, and suddenly her agency collapses into waiting for one of them to choose her back. The show knows this contradiction exists. It never pretends the girl stays the fighter she started as once the boys arrive. The romance dissolves her into someone passive, which is exactly what the premise demanded it would do.

Aida Nonoka owes her life to a stranger. When a drunken man attacks her, a judoist steps in and saves her, and the only clue she has to who he was is a scar on his back. Inspired, she resolves to become as skilled as her rescuer, hoping that one day she will recognize him by that mark. After transferring to a new high school, she meets two older boys, and either of them might be the man who saved her and the one she will give her heart to. Across two OVA episodes, the story pairs action with romance as Nonoka searches for her savior.