Mayuka Kondō holds the position of class president in Shuusuke Takanashi's class, presenting herself publicly as a diligent and approachable student admired by classmates. Secretly, she harbors a passionate obsession with Boy's Love manga, which she meticulously conceals to protect her social standing. Her first major encounter with Shuusuke unfolds when their bags are mistakenly exchanged one night, resulting in him acquiring her BL magazine while she inadvertently takes his adult publication. To reclaim her property, Mayuka adopts the alias "Mr. X" and blackmails Shuusuke, threatening to destroy his magazine unless he cooperates—exposing her strategic, covert nature that contradicts her affable facade.

When Shuusuke panics and destroys her BL magazine after uncovering her identity, she establishes a compensatory agreement designating him as her "pet." This arrangement compels him to purchase explicit BL materials she deems too embarrassing to buy herself and provide objective reviews, which she misreads as authentic enthusiasm for the genre. She manages this relationship transactionally, rewarding his obedience with head pats or homemade meals devoid of romantic intent, while Shuusuke misconstrues her actions as hints of a dominant-submissive dynamic.

Mayuka's view of Shuusuke shifts when she notices his "pink and sensitive" nipples, which evoke BL character traits due to her inexperience with actual male anatomy. This curiosity prompts impulsive touching during chance encounters. She slowly cultivates genuine romantic feelings, crediting his nonjudgmental stance toward her BL interests. During a critical moment, she openly confesses a wish to emotionally dominate him. This admission is instantly erased from her memory when a truck collides with her shortly afterward, freezing any progression of these emotions or their impact on their relationship.