Called "The Obsessed Man" by the townspeople because he loses sight of everything else once he's focused on one thing. He falls in love with Pechka, the balloon seller, and runs around frantically for her sake. He can talk to Cielo because he has mastered the language of mice.

A girl who came from a foreign country to the east. She lives in an apartment on the edge of town with a single parakeet while selling balloons to pay for her sick mother's treatment. She is happy to have Giuseppe as her first friend, but there is a slight shadow in her smile. She can talk to Cielo because she worked hard to understand the language of mice.

A mouse who lives with Giuseppe as his friend. He can only talk to Giuseppe and Pechka, who know the language of mice. An eccentric who eats the same food as humans and prefers a clean lifestyle. He busies himself trying to play matchmaker for Giuseppe and Pechka.

The boss of the town's gang. He takes balloon-selling fees from Pechka as debt payment. He has a flashy personality and loves the twist dance, but he has another hobby he's kept since he was a boy.

A gang boss who is in a turf war with Boss Twist. He looks very sickly/pale.

She has a terrible cough and has been hospitalized in a mountain clinic for about two years. She is unable to speak due to swelling in her throat. Thanks to Giuseppe, her voice has fully recovered, and she can now sing beautifully.

A schoolteacher who teaches ice hockey to children in a foreign country. He is Pechka's fiancé. He speaks kindly. In truth, while heading to a hockey match, the gondola malfunctioned; he jumped off to lighten the load and passed away.