The Neighbours Are Secretly Laughing (1999)

Rinjin wa hisoki warau season 1

The story starts with a serial killer, whose victims are lone women and acts are perpetrated in Mizuno Maki's neighborhood (it is suggested that Motoki is this serial killer). Motoki is a police officer with 2 faces: he has an obsession for housewife Maki and is very gentle with her, and on the other side he rapes & tortures one of her friend, Kanda Uno. His ultimate goal seems to make Maki fall in love with him: so he uses her friend Uno to affect her relationship with her husband & he gradually introduces himself into her life. Another person is also obsessed with Maki (she is a sort of public personality as she runs a cooking club with other housewives and appears in magazines), harassing her all the time on the phone, spying on her, etc...: this person is close to her as he knows things from her past (her son drowned in an accident). Motoki also had an ordeal in his past: his mother was killed in a fire, by her lover.