"If there is no one who listens, nowhere for the bitterness to go, then one day the heart will break."
One day after work, Suzuki Kenji is stopped by Saya, a high school girl. She asks him for money, and, eventually he becomes her confidante, her partner in crime, her only friend. They meet up in a park few people go to, on a bench no one ever sits on, a quiet island in the middle of the city. Here they talk about their lives, their secrets - and something they plan on doing, something that no one can find out about.
Suzuki Kenji continues to live his life: Go to work, meet new colleagues, dealing with the flow of adulthood. Saya's existence is just a small, insignificant part of his life. She's all trouble and no benefit. But he always ends up back on the park bench. Because he knows she is waiting for him.