Lily is a young girl, who appears to be introverted, melancholy and timid. She couldn't decide where she should stay during the summer vacation of high school. Then, she took a coin and threw it into the air to decide whether to go to her mother's or father's place. Ever since junior high school started, she has used coins to decide on her "home" every summer vacation. Lily, who stayed at home, lost every day of vacation to boredom. One day she was in the paragliding field and met a girl named Lili who was bold, free and self-assertive. Her life turned upside down with the curious love of adolescence and girls' fooling around with each other...