As collateral for his brother's debt, his brother Tsutomu begins to treat his sister-in-law Satsuki as his sex toy. His nephew Kenji joins in and they all turn Satsuki into a sex toy. Satsuki tries her best for her beloved husband, but she gradually awakens to pleasure through intense training such as electric microphone caging and double irama... Satsuki is no longer just her husband's.