Suzume Yamada is an unassuming high school girl with a secret: at home, she sheds her mousy persona to become a full-blown otaku, obsessing over the handsome characters in her favorite dating sim games. Her carefully separated worlds collide when Kei Yamada, the most popular and seemingly perfect boy in school, discovers her secret. To Suzume’s horror, he also shares the same last name. Kei, who is secretly a massive fan of magical girl anime, blackmails Suzume into a contract: she must pretend to be his girlfriend to fend off his throngs of admirers, and in return, he keeps her otaku lifestyle under wraps.

Set in a typical Japanese high school and the surrounding city, the story expands from the duo’s tense partnership to include their eccentric friends and classmates. One major early arc focuses on "The Cultural Festival," where a school-wide competition forces Kei and Suzume to participate in a couples’ cosplay contest, testing the limits of their fake relationship. Another notable arc is "The Summer Retreat," where the group goes to a hot springs inn, leading to a series of comedic misunderstandings and a jealous confrontation with a rival character who has a crush on Kei. As the narrative progresses, the lines between the performance for the public and their true feelings begin to blur, moving from a simple blackmail setup into a story about insecurity, shared hobbies, and genuine romance.