Yuto is a 5th grade elementary school student. He lives with his younger sister Misa and his parents Sakuro and Keiko. His parents run a restaurant together. Yuto's life goes well for a 5th grader. His friend Takashi lives with his mother, but Takeshi's mother neglects him. Because of this, Yuto's parents often invites Takeshi to have dinner with them. One day, Yuto and Takeshi meet sisters Michiru and Hikaru. The sisters are living in a car with their father, but, several days later, their father goes missing. Only, Michiru and Hikaru are left behind. (Source: AsianWiki)