Mari Monro (門呂 マリ), also known as Marilin, is 27 years old. She is a somewhat clueless and extremely cheerful and beautiful woman. She dazzles everyone who sees her. Her name is based on Marilyn Monroe.
She has a 7 year old son, Osmaru Monro (門呂 オサム), who goes to the second grade and has not appeared in the anime.
She found an cat who was later called Marilin.