; :The town
mouse, who calls himself , he is always energetic, full of curiosity, and has a strong sense of justice. He takes a trip to show the sea to his close friend Bōbo, and meets Chūta at the harbor when they arrive. Gamba and his friends are out on a journey to heed the wishes of Chūta, to defeat Noroi who rules Noroi Island. He is renamed
Gavin in Lionsgate's English film dub. ; :The Gamba's best friend, he is a gluttonous, green-furred and an easygoing town mouse. His name is the result of him being absentminded. His sensitive nose helps him to find food. He is made into a secondary character in the 2015 film. ; :A mouse who appears only in the 2015 film, he takes on Bobo's original role from the 70s anime. He is renamed
Matthew in Lionsgate's English film dub. ; :The kind-hearted captain of sailor mice, he has a girlfriend named Yuri, is highly dependable and is calmer than Gamba. He lost his right eye to Noroi. He is renamed
Rusty in Lionsgate's English film dub. ; :One of Yoisho's childhood friends, he is knowledgeable, clever, wears big glasses and has quite a short tail. He is renamed
Grayson in Lionsgate's English film dub. ; :The wandering doctor mouse, every time he gets drunk, he reads poetry out loud. He also has sensitive ears that pick up sound the other mice cannot hear. ; :Ikasama is a gambler and good at fraud. He is also called a "swift runner" because he is light-footed. He is renamed
Ace in Lionsgate's English film dub. ; :An insular mouse who comes to the town for help. He is a younger brother of Shioji. He is renamed
Chester in Lionsgate's English film dub. ; :The leader
weasel with snow-white fur and red eyes. He is a cruel and bloodthirsty killer and when his red eyes shine eerily in the dark, he can apply hypnotism. He is renamed
Winston in Lionsgate's English film dub. ; :The granddaughter of the elder mouse Shuro from Yumemishima, and is an older sister of Chūta. She is renamed
Shelly in Lionsgate's English film dub. ; :The traveler mouse who is on his way home from a ten year trip. He uses Gamba to avoid danger. He is modeled on Torajirō of "
Otoko wa Tsurai yo". ; :The head of the
streaked shearwaters. All of his subordinates, his wives, and his eggs were slaughtered by Noroi. Tsuburi is depicted as female in the film, and she is renamed
Theresa in Lionsgate's English dub. ==Voice cast==