Hina has admired Takeru since childhood. However, Takeru marries Hina's sister, making him a more distant figure in her life. She's still happy to be working alongside him as a teacher at the same school. Unfortunately, Takeru's father, Gouzou, becomes aware of Hina's feelings. Although she has a youthful face, her body is maturing as a woman. Gouzou sets a trap to make Hina his own.

Takeru married his childhood friend, Haruka. His career as a teacher at their old school is going well, and he receives positive feedback from colleagues and students. When he returns home, his beloved wife Haruka greets him with a smile. Takeru feels fulfilled and happy both in his personal and professional life. However, unbeknownst to him, his happiness is threatened by his own father and Haruka's father-in-law, Gouzou. He demands Haruka's body in exchange for helping Takeru out of a difficult situation. Haruka agrees to have a one night stand with Gouzou, on the condition that Takeru never finds out.