Kotone Aizuhara is a university student and self-identified fudanshi whose life ends abruptly when a truck collides with him during a boys-love manga purchase. This accident transports him to an alternate world devoid of women, governed by unfamiliar social and biological rules.

Upon arrival, he encounters Nagi, a divine serpent in human guise, who declares Kotone his bridegroom. Nagi explains their obligatory sexual relationship is crucial for his ascension to a higher dragon form. Leveraging his extensive BL knowledge, Kotone instantly recognizes the narrative tropes at play, accepting his destined submissive role.

Kotone's prior immersion in boys-love narratives becomes his primary survival mechanism. He strategically applies this expertise to decode interpersonal dynamics and power structures within the all-male society, maintaining deliberate emotional detachment to avoid romantic entanglement while fulfilling his obligations. The narrative leaves his success in resisting deeper emotional involvement ambiguous. Kotone's interactions consistently center on adapting to his new reality through specialized knowledge, with no significant character evolution or expanded backstory beyond this foundational premise.