Tokyo Butei High School is a specialized institution where the Butei, armed detectives, receive training in firearms handling. Kinji Touyama, a second-year student, has a unique talent that causes him to grow almost superhuman strength when stimulated by the opposing sex. He conceals this, nevertheless, in order to lead a normal, quiet life as before. His tranquil school days come to an abrupt end, however, when he is trapped in a bombing while en route to school and encounters Aria H. Kanzaki.
