Yuuhi Katagiri, daughter of the affluent Katagiri family, transfers schools after a life of sheltered strict supervision. Her striking beauty routinely draws unwanted male attention, necessitating rescues like Junichi Nagase's initial intervention. She specifically enters Junichi's school to find her arranged fiancé, unaware of his identity. A significant misunderstanding erupts when Junichi publicly kisses her during their first school meeting, igniting deep humiliation and hostility. This event triggers her tsundere demeanor, marked by formalized verbal aggression—her recurring threat "I'll have you dead!"—masking underlying vulnerability.

Her mother is deceased, leaving Yuuhi a cherished hair clip memento. The arranged engagement results from a debt her father owes to Junichi's parents, who saved his life. Mandated by their parents, she cohabitates with Junichi to evaluate his suitability as a husband while documenting his flaws. Her sheltered upbringing manifests as naïveté towards mundane activities: astonishment at instant curry during a supermarket trip and disastrous cooking attempts causing kitchen explosions. Initial animosity towards Junichi's sister Minato gradually shifts to cooperation, including joint school festival efforts. Her feelings for Junichi evolve into genuine affection, though she struggles with direct expression.

Adaptation outcomes differ: the manga concludes with mutual romantic commitment between Yuuhi and Junichi. The anime diverges, showing Junichi ultimately choosing Minato despite Yuuhi's persistent affection. A sequel hook implies her unresolved pursuit as she moves back into their household, vowing not to relinquish her claim on Junichi. Additional traits include covert curiosity, evidenced when snooping in Junichi's room leads to discovering his porn stash. Her narrative role involves challenging harem tropes by confronting Junichi about his emotional indecisiveness in later story arcs.