Incest mother-child favoritism

Ayaka and her son Satoshi are left behind after the sudden disappearance of her businessman husband. When Satoshi quits school and starts working part-time for his mother, Ayaka ends up hiding her husband, who doesn't know if he's alive or dead. Lewd fantasies about her son run through her mother's head. Ayaka feels that if she continues like this, she will end up in an inappropriate relationship with her own son, and begins to have sex with a stranger she met on a dating site. The son who has learned the true nature of such a filthy mother...