Ryō Sakaguchi is a high school student sporting spiky brown hair, golden eyes, and a distinctive mole beneath his left eye. His defining passion is being a fudanshi: a heterosexual male deeply engrossed in boys' love media like manga and doujinshi. This fascination consumes his daily life, fueling frequent imaginings of BL scenarios involving classmates, though he feels no romantic or sexual attraction to real-life homosexual relationships.

Initially self-conscious about societal views, he feels embarrassed purchasing BL materials from the "girls" section of bookstores and hides his hobby from peers, fearing judgment about his sexuality. Despite this, he remains eager to discuss BL tropes, shipping dynamics, and doujinshi culture whenever possible, often explaining these concepts.

His social circle includes Nakamura Toshiaki, a close friend who tolerates Ryō's BL obsession but occasionally questions his orientation. He befriends Nishihara Rumi, a fujoshi who becomes a key confidante. Through Rumi, he gains confidence to attend events like Comiket, deepening his fandom involvement. He also interacts with Shiratori Yūjirō, the flamboyantly gay crossdresser leading the school's cooking club, and Ueda Akira, Shiratori's devoted yet ostensibly non-gay admirer. These relationships offer comedic contrast, as Ryō shows less interest in their real-life dynamic than in fictional BL narratives.

A significant development occurs when Ryō discovers Daigo, a fellow male classmate and secret BL doujinshi-creating fudanshi. This connection eases his initial isolation. Throughout his experiences, Ryō navigates recurring misunderstandings where peers mistake his BL fandom for personal homosexuality. Despite these challenges, he gradually becomes more open about his hobby, finding camaraderie with like-minded individuals while steadfastly maintaining his heterosexual identity.