Yasuko Hanaoka is a divorced, single mother who thought she had finally escaped
her abusive ex-husband Togashi. When he shows up one day to extort money from
her, threatening both her and her teenaged daughter Misato, the situation
quickly escalates into violence and Togashi ends up dead on her apartment floor.
Overhearing the commotion, Yasuko's next door neighbor, middle-aged high school
mathematics teacher Ishigami, offers his help, disposing not only of the body
but plotting the cover-up step-by-step. When the body turns up and is
identified, Detective Kusanagi draws the case and Yasuko comes under suspicion.
Kusanagi is unable to find any obvious holes in Yasuko's manufactured