After being stood up for a movie date, Fumihiko Matsumaru, a marketing employee, contemplates ditching his tickets. His plans come to a halt when Aka Onda, a girl bursting with unique energy, implores him to let her join him instead. As they take a stroll back home, they realize they live in the same neighborhood. Their night finds a sad end when Aka's apartment, and her personal belongings burn down, but Fumihiko offers her a place to stay. This decision leads them to have a one-night encounter, which changes the course of their lives, both personally and professionally. Despite their initial circumstances, Fumihiko and Aka decide to live together in a platonic manner. They soon discover that Aka is the voice behind the mascot designed for Fumihiko's company's new product. In an attempt to conceal the truth, they agree to keep their cohabitation a secret. Through their mutual experiences, they bond while enduring work challenges and provide each other the support they need to succeed.