Chibi Maruko chan is the nickname of a sweetly obnoxious 9-year-old girl. She tricks her grandfather, ponders for hours over how to spend her allowance, and hates sitting next to ugly boys. She talks, feels and lives just as real kids do. As the second term commences, Maruko and her classmates return to their small groups. Maruko’s group includes two naughty boys and Maruko is forced to be one of their subordinates. She seems to face a lot of pressure at school.

Momoko's teacher asks the third grade to draw a picture based on their favorite song, to enter in a contest. She picks a song she's recently become fond of during music class, and is anxious to make a good drawing based on it. On her way to meet relatives in Shizuoka, Momoko meets Shoko Kimura, a university student who occasionally draws portraits and plans to participate in an art contest. Momoko and Shoko become close friends, and end up inspiring each other both in their own ways.

Students from five different countries arrive in Maruko's town. Maruko and her classmates can barely contain their curiosity, and their new friends are full of surprises. And Maruko's family will house a boy from Italy!

Maruko, who has jumped out of her everyday life, travels on a mysterious adventure in a new world of fantasy.