Yoshihito, a 23-year-old unemployed man living alone in his inherited family home, faces financial strain until renting a room exposes him to the supernatural. His first tenant, Lily, appears human but unveils her werewolf nature during an attack by Vivian, a sharp-tongued vampire. This clash thrusts Yoshihito into a hidden world of mythical beings, prompting recruitment by a covert organization tasked with preserving balance across parallel universes. His new role mandates fostering coexistence among species, requiring him to host additional supernatural tenants in exchange for steady income and benefits.

As he mediates disputes between factions like Witchers and extraterrestrial rivals, Yoshihito’s life becomes a precarious blend of mundane chores and interdimensional diplomacy. His home evolves into a microcosm of interspecies dynamics, where routine interactions with tenants like Lily and Vivian spark recurring clashes between primal instincts and vampiric wit. The narrative traces his pragmatic adaptation to escalating responsibilities, emphasizing external challenges over internal reflection, as he navigates both domestic tensions and cosmic-scale negotiations.