Bondage slave stepmother tied up and raped in his son's place...

Natsume is her mother who lost her husband a year ago and lives a modest life with her son-in-law Jun. One day, when Natsume returns home, a tragedy strikes him! A strange yakuza-like man had come into the house without his permission and threatened Jun with a loud voice! "Hey, you made my precious daughter pregnant," the angry man pushes Natsume down on the spot and rapes her, just as if to give him back. The man's anger that caused his daughter to be damaged cannot be resolved by itself...