Yuuhi Katagiri, the esteemed daughter of the Katagiri family, finds herself in a predicament when she walks home alone and encounters trouble. Junichi Nagase, known as the 'Geno Killer', steps in to help her, leaving Yuuhi intrigued. The next day, Yuuhi transfers to Junichi's class and labels him as the 'Geno Killer', sparking gossip. Their situation worsens when a misunderstanding leads to a kiss, unveiling that Junichi is actually Yuuhi's fiancé. Despite Yuuhi's initial disdain for Junichi, she is bound by her father's decision to live with him and prove his incompetence as a husband. As they cohabit, will Yuuhi succeed in her mission, or will unexpected feelings develop between them?