Yuki Kurihara, a second-year high schooler, has finally collected the confidence to ask her first-year crush Shinya "Momo" Momotsuki out after capturing one hundred hidden photographs and monitoring him from afar for months. Despite being taken aback, the shy Momo agrees; nonetheless, he is unaware of the truly unorthodox reality. As her strict friend, Norika Mizuyama, has noted, Yuki has acquired some unsettling—but very genuine—habits, such as secretly photographing Momo, conducting extensive research into his personal life, collecting his used straws, and even going "Momo watching." Momo is blissfully ignorant of his new girlfriend's strange tendencies, although he does detect certain abnormalities in their everyday chats. Momo, who is still hesitant and scared about his first relationship, finds himself in unpleasant situations on a daily basis.