After her first sexual experience in junior high school, Yuri was precocious when it came to sex, and as a high school girl she secretly obtained SM magazines and loved to read them, and longed to become a masochistic woman. During junior college, she was trained by her sadistic boyfriend, and came a little closer to her ideal masochistic woman. However, the relationship didn't last long, as he was having an affair, so she found a safe boyfriend at her workplace and got married. They had a child and built a family that seemed happy at first glance, but she grew tired of her husband's monotonous sex, and met an older man...