Mizuki Yoikawa (31), who is unable to have a boyfriend and has a series of bad luck with her company going bankrupt, returns to her parents' home after a long absence and meets Ren Hebimori (20), a mysterious younger boy. She comes to know his insane nature and is half-forced to become his lover. Furthermore, the words to the next step from his mouth early, "I want to say a wedding greeting." When she reluctantly took him to her parents' house, he met her mother and her cousin Sho-kun, who seems to have helped her with the shopping. He can't hide his jealousy at the presence of a man who is close to her, even though he's a relative. And while her mother is very supportive of the marriage, her cousin calmly tells her that Hebimori is still a student and that it's too early. Ren-kun begins to run wild against negative opinions about their marriage. In order to avoid the worst situation, she should have just calmed him down.. This is the story of a young yandere boy who is sweet and doting and a little bit brutal and disturbing]