Tsubasa lives with his retired father-in-law. His father-in-law does a lot for Tsubasa, who is busy at work, but inside his heart, a rotten desire swirls. He has been eyeing Tsubasa's lewd body. Not content with staring at her defenseless big breasts, Tsubasa's father-in-law purposely falls so he can get his hands on her body. Not realizing for a second that it's a trap, Tsubasa hurriedly helps his father-in- Tsubasa up, only to find that his father-in-law, with a fearless smile on his Tsubasa, embraces him...!?