In early summer, 2nd year of high school, Koguma's mom suddenly leaves, leaving only a note that says "Bye." She is alone, having no parents, no friends, no hobbies. She silently reflects, "I don't have anything." But a chance encounter results in her buying a Honda Super Cub with a disturbing history, and a new life suddenly blossoms open.

In early summer, 2nd year of high school, Koguma's mom suddenly leaves, leaving only a note that says "Bye." She is alone, having no parents, no friends, no hobbies. She silently reflects, "I don't have anything." But a chance encounter results in her buying a Honda Super Cub with a disturbing history, and a new life suddenly blossoms open.