Reina, a mother, is troubled by her son Takeshi's reclusiveness. She is at a loss as to what to do, but her friend Matsuoka is the only one who comes by frequently to encourage her. One day, in an attempt to impress Takeshi, who was on the track and field team, Matsuoka suggests that they go jogging together. Rather than doing nothing, Takeshi takes up the suggestion and the two of them start running the next day. Takeshi follows their backs as they run happily, feeling envious of them, and leaves the room to call out to them when they return, but to his surprise, they are lying together in bed...