Shoma transforms into Kamen Rider Gavv. He loves snacks and works at HapiPare. He is the youngest son of the Stomach family, referred to as 'Red Gavv' by the Stomach Corporation. He is a half-human, half-Granute.

Hanto Karakida transforms into Kamen Rider Valen. He is a freelance writer who was modified by Kenzo Suga, enabling him to transform into Kamen Rider Valen.

Lakia Amalga transforms into Kamen Rider Vram. He loves stones and his catchphrase is 'Daru' (what a drag). In the Granute world, he used a fake name and was once in Lage 9. He had a younger brother who passed away.

Kenzo Suga transforms into Kamen Rider Bake. He is the researcher who modified Hanto Karakida and developed Bitter Gavv.

Dark Shoma transforms into Kamen Rider Bitter Gavv. He is a being created by Kenzo Suga.

A researcher and the one who developed Vram's belt. He is the older brother of Shoma and Jeeb, and the second son of the Stomach family.

The president of HapiPare and a gyaru. She calls Gavv 'Umasho', Valen 'Hanty', and Vram 'Lakian'.

The older brother of Nielv, Shoma, and Jeeb. He is the president of the dark snack company, Stomach Corporation. He has an asymmetrical wolf cut with red point mesh highlights. He is the eldest son of the Stomach family.

The younger brother of Lango and Nielv, and the older brother of Shoma. He transforms into Kamen Rider Bitter Gavv Bakibaki Stick. He has no connection to the other Dark Shoma Bitter Gavvs. He is the husband of Glace Jardack and is kind to her. He is the third son of the Stomach family.

Jeeb's wife. She is a curious only daughter of a wealthy family. She wears a blue dress and carries a blue umbrella, with silver hair.