Shinkuro Kurenai is an orphan; he attends high school, studies martial arts, and does not shy away from various odd jobs, including dangerous ones: he takes down ruffians, catches hooligans, and so on. His employer, the extravagant and risky Bénica-sama, offers Shinkuro a new assignment – to protect little Murasaki Kuko-in, the daughter of an influential yakuza. It seems that for Shinkuro this is a job in his field, but besides ensuring the safety of Miss Murasaki, the young bodyguard is also given duties that are completely unfamiliar to him: caring for, feeding, bathing, and disciplining a willful six‑year‑old.