Living alone and struggling to survive in a difficult environment, Ayato works part-time to make ends meet. When his mother suddenly reappears and leaves his young sister in his care, Ayato turns to City Hall for assistance. He hopes to enroll his sister in a nursery while he works, but instead of offering help, he encounters Haruna. A serious and diligent employee, Haruna criticizes Ayato without knowing his situation, comparing him to an irresponsible cat. Enraged by the harsh words, Ayato retaliates, "How would you know anything about me?"
Despite their initial conflict, Ayato and Haruna gradually heal each other's past wounds and develop a mutual attraction. Struggling through difficult times, what promises will these two make to one another? Can they truly trust and rely on each other?
