Kösaku saves a girl from delinquent members of Kokuryu High Schools boxing club, so they decide to beat up Kösaku, until Hibari beats them up instead. The girl, Koenji Sayuri, develops a crush on Kösaku. A strange man harasses Tsubame and Suzume then breaks into the Özora house and peeks on Hibari in the bath. This gives Ibari another heart attack. The man turns out to be Shirachi Kogoro, a private detective hired by Sayuri to investigate Kösaku and his relationship with Hibari. He discovers that Hibari is a boy. Sayuri swears to defeat Hibari and take Kösaku, revealing her darker, evil side...