Watari Hirokuni, a salaryman, is pressured by his power-harassing boss and overwhelmed by his job, leading him to live sleepless nights. One day, he is suddenly approached by a mysteriously beautiful young man. It turns out to be Fukaya Kai, a close friend from middle school days. About ten years have passed since then, and the now-adult Kai appears before Hirokuni. Claiming to have nowhere to live, Kai crashes at Hirokuni’s place and starts cooking meals every day, making it a condition for their cohabitation.