Based on the novel of the same name by Azusa Katsume.

Rei, the deadly but reluctant assassin for the Zero Division of the Tokyo Police Department, befriends a young man after she sees him cruising a gay bar looking for johns. After he gets beaten up by a group of street thugs, she takes him in to live with her. When a series of vicious murders takes place, she begins to suspect that the killer may actually be her friend taking revenge on everyone who has abused him. Will she uphold her duty to the police, or protect her only friend?

Maiko is a recently widowed young woman travelling to Bali to distract herself from the loss of her husband, Esau. At the airport she meets Kioko, who gives her a dagger and a photo of a woman. She tells Maiko she must find the woman, Shireni, in Bali and convince her to return to Japan, or she must use the dagger to kill her. Soon after her arrival in Bali she meets Shireni and is invited to stay with her. Quickly Maiko finds herself trapped on Shirini's island paradise, by her own confusion and her developing love for Shireni. She discovers Shireni to be immortal, a former spirit medium whose only goal is to find pleasure, body and soul.