Natsuko had been widowed for 10 years and was living with her stepson and father-in-law. Though financially comfortable thanks to her late husband's insurance, she felt a growing emptiness driven by her intensifying sexual desires. Since her husband's death, she had avoided relationships with men and suppressed her urges alone—never expecting to become entangled with her "stepson" and "father-in-law."
  [KSBJ-402] Edge of Incest: My Flesh Receptacle for Father-in-Law and Stepson - Kayama Natsuko