Mayu is a young teenage girl who ran away from her abusive family, becoming homeless in the process. Living on the beach and subsisting on bread crusts with a small puppy, Wanta, that accompanies her. She ends up living with Kouta and Yuka as her legal guardians, and later befriends Nana and tries to take her under her wing. Mayu is kind and friendly towards everyone, she tries to bring out the best in everyone, and maintains an idealistic view of the world despite her trauma.