At a nearby high school, Kazuma Kadomae assumes the position of homeroom teacher and takes the time to familiarize himself with all his students. Amongst the pupils is Kanade Noeda, the principal's daughter, who appears to be more introverted than her peers. Despite his good intentions, Kadomae's attentiveness unintentionally leads Noeda to develop an unrequited love for him, morphing into a delusional obsession.
Kadomae grows increasingly alarmed by Noeda's unconventional advances towards him, and his efforts to dissuade her only amplify her infatuation. The situation soon escalates when a student involved with Kadomae is injured, and Noeda's unwanted pursuit turns into her stalking Kadomae and his family. It soon dawns on Kadomae that Noeda will stop at nothing to claim her place beside him.
