Fantastical Moon Street is inhabited by children who refuse to grow up, refuse to go to school, and only wish to play freely—yet lack the ability to live independently. The Crystal Elder, who is the incarnation of Grandfather Sun, fulfills their various wishes. He also sends three children from the Sweet Family and a tiger-faced man to Moon Street, where they join the forever-young children in establishing a normal life. Together, they defeat the Great Rat Demon King of the Death Castle, helping the children improve their independent living skills and sparking their interest in seeking knowledge.