One day, a 15-year-old girl comes into 'hard-boiled' detective Kataoka Heihachirou's office. The girl, Mizunomori Taira, gives him the shock of his life when she announces that he is her father! Her mother, Seiko, had died in a traffic accident, and Taira had decided to seek out the father she had never met. Heihachirou may be crass, sloppy, sexual and have no idea how to care for a daughter, but he takes her in. Taira and her "heart-boiled" detective papa begin their daily life together, a life neither of them could have expected!