After returning from an overseas business trip, Shinji stays at his brother's house. His sister-in-law Aki is incredibly ditzy and clumsy! She flashes her panties and barges into the bath without realizing it, constantly tempting him unknowingly. One night, drunk Aki demands 'Rub me more,' leading to forbidden sex next to his brother! The next morning she had lost her memory, but her body couldn't forget the pleasure and unconsciously set up a night trap!
