Chouko Manaka is the next heir to the prestigious Manaka family. Now entering high school, she has had enough of being surrounded by bodyguards, who have prevented her from making any friends. Her father remains worried, however, so he makes a deal with her: if she transfers to Mizonoo High School, where many students are also training to be shinobi, and manages to secure one of them as her right-hand man by graduation, he will consider her capable of making her own decisions. On the first day of school, Chouko meets the son of their butler, who suddenly declares that he wants her to be his master?!