Shouichi, who lost his mother at a young age, lives with his father. One day his father remarries a woman named Yuuko, who is young enough to be his sister, and Shouichi struggles to accept her. To improve their relationship, Yuuko suggests they attend a week-long camp event aimed at improving communication between parents and children. She joins Shouichi in attending the camp, and the story follows their journey at the event, exploring whether Shouichi can come to accept Yuko as a mother figure and how the experience will change him.