Mahiru is a beautiful girl who became aroused by her father after peeping on her parents having sex as a child.
One day, she is introduced to a man who could become her new husband, and it turns out to be Kotaro, the man she had previously had a relationship with as her fake "father."
When Kotaro comes to stay at her house, Mahiru spies on her mother having sex and indulges in masturbation. However, her mother passes out before Kotaro can satisfy herself.
Disappointed, Mahiru starts sucking on her "father's" dick instead, becoming immersed in the pleasure she has always craved...