The main character Yoichi Sakuragi lives alone in a cheap apartment with his mother Shino Sakuragi. Living without a father was not easy, but the two supported each other and had a simple but happy life.

Yoichi loves his mother, Shino smiling as she says " If only Yoichi is on my side, she would be happy." Ryo, Yoichi's best friend was also attracted to Shino as the opposite sex and he was listening to the opportunity to convey his feelings of love, being careful not to be notice by Yoichi.

One day Ryo, who can no longer control his feelings, lies to Yoichi and visits the apartment where his mother and child live while Yoichi is being tricked out. Ryo who succeeded in becoming alone with Shino, hugs Shino who is preparing tea from behind and forcibly robs her lips.

"I've always liked Shiono-san" Ryo was surprised when Shino told him that she still loves her dead husband and that she can't date her son's best friend. However, Ryo who thought that he was rejected, runs out of control and pushes Shino on the floor, forcibly forming a physical relationship. Shino who had not sex for a long time since her husband passed away, felt guilty about her husband and son, but got pleasant feelings with young and powerful Ryo.

After that, Ryo asks for Shino's mature body every time she goes to work, at the mother and child's apartment, where she works part-time. Even though Shiono knew that it was a bad thing, she was gradually deprived of not only her body but also her heart before Ryo desperately sought herself.