Yuya Amae, a worn-out office worker, encounters Shiratori Aoi, a charming high school girl from his past. Aoi, now skilled in household chores, asks to move in with him under the guise of future marriage. Despite his initial bewilderment, Yuya consents to this living arrangement, albeit as a temporary guardian. Yet, Aoi's flirtatious advances threaten to test his determination.