College student Ena is popular as a private tutor—sweet, flirtatious, and skilled at teaching. Shu, who attends an all-boys school and has little experience around girls, finds himself constantly flustered during her lessons. So much so that he always ends up horny and masturbating afterward. One day, he decides to secretly hide his phone under the desk to peek under Ena's skirt during class. That single moment becomes the turning point that drastically changes his life.