The film centers on Riko Murakami, a tough-as-nails detective who is also the single mother of a young boy. At work, she has hit a wall investigating a grisly murder in a hotel room. In her private life, she sweats her son's impeding "park debut" -- when she introduces her son and herself to the young mothers of her neighborhood. Most give her strange almost hostile looks except Sachiko (Keiko Unno), who says her kid is in the hospital. While her son gambles about the playground, Riko and Sachik...