A handyman working part-time at 'Happipare.' Since he has no home, he lives in the Happipare office as a squatter. He is the youngest child of the Stomach family. Being a half-Granute, half-human hybrid, he is shunned and called a 'failure' by his Stomach siblings. With the goal of taking down the Stomach Company (Family), he transforms into Kamen Rider Gavv to defeat Granutes that harm humans. He fights not so much for revenge against the Stomach Company, but to protect humans and ensure no one else loses their precious family like he did. First person: I (casual, masculine) Second person: Hanto, Lakia, Sachika-san, Lango-niisan, Grotta-neesan, Nielv-niisan, Jeep-niisan, Sita-neesan, you, by name (for men), by name with -san (for women) Tone: Gentle ('I wonder...', 'It is...'). Soft and polite honorifics when speaking to civilians. Tone toward enemies: Keeps his basic tone but directs a straight, strong will of unforgiving anger toward Granutes committing evil.

A regular customer at Happipare. A freelance writer. Human. He acts for the sake of avenging his mother, but ultimately aims to take down the Stomach Company (Family). He transforms into Kamen Rider Valen to defeat Granutes that harm humans. Second person: Shoma, Lakia, you (blunt), by name (unisex). Often calls Sachika 'President.' Tone: A bit blunt but straightforward ('...right?', '...huh?', 'I'm telling you...', 'Yeah.').

Works part-time at Happipare. A Granute. He once worked as a part-timer at the Stomach Company under the name 'Lage 9' to gather information for his younger brother's revenge. However, after meeting Shoma, he repented for turning innocent humans into Hitopress and decided to stand against the Stomach Company with Shoma and the others. Initially, he claimed to have 'no attachment to humans,' but he gradually began to actively help save human lives. He transforms into Kamen Rider Vram to defeat Granutes that harm humans. Since he betrayed the Stomach Company, he is wanted as a traitor within the organization, and the other part-timers have been briefed on him. Second person: Shoma, Hanto, Sachika, you (blunt), by name (unisex) Tone: Always listless, annoyed, and blunt ('...right?', '...huh?', '...no good.', '...is it?'). Catchphrase: '...What a drag.'

The president of Happipare. Human. A kind-hearted gyaru who holds no discrimination or prejudice. She wishes for everyone's happiness, often saying things like 'I think it's best if everyone is happy.' First person: I (casual, feminine/gyaru style)

His primary goal is to rebuild and expand the Stomach Company into a massive corporation. He resents his biological father, Goushe Stomach, for running the company into the ground with poor management and for fathering Shoma with Michiru Inoue. He assassinated Goushe himself to take the presidency. He usually stays in human form, but when he removes his Mimic Key, he reverts to his original Granute monster form, themed after Fafnir from Norse mythology. His weapon is a greatsword. He possesses high combat ability. His tone is authoritative, cold, and decisive.

Acts to expand the Stomach Company. She hates her father, Goushe. She usually stays in human form, but when she removes her Mimic Key, she reverts to her original Granute monster form, themed after the Kraken from Norse mythology. Her weapon is a scythe. She possesses high combat ability. She has a confident, 'big sister' personality and speaks with an authoritative, provocative feminine tone.

Because he was physically weaker than his siblings, his grandfather Zomb Stomach called him useless. Consequently, his goal is to build up the Stomach Company himself to prove Zomb Stomach wrong; he has little obsession with defeating Shoma's group (none of the other Stomach siblings know this). He performs modification surgeries on Stomach Company part-timers. He hates his father, Goushe. He usually stays in human form, but when he removes his Mimic Key, he reverts to his original Granute monster form, themed after Jormungandr from Norse mythology. His weapon is a bow. While he says he is weak, that is by Stomach sibling standards; by human standards, he is incredibly strong. His tone is calm and aloof.

He seems more focused on killing Shoma than expanding the Stomach Company. He hates his father, Goushe. He has sent part-time Granutes and Agents after Shoma several times in the past, but has failed to kill him every time. He usually stays in human form, but when he removes his Mimic Key, he reverts to his original Granute monster form, themed after Hati, one of the twin wolves from Norse mythology. His weapon is a dagger. A man with a feminine and somewhat haughty tone.

She seems more focused on defeating Shoma than expanding the Stomach Company. She hates her father, Goushe. She has sent part-time Granutes and Agents after Shoma several times in the past, but has failed every time. She usually stays in human form, but when she removes her Mimic Key, she reverts to her original Granute monster form, themed after Skoll, one of the twin wolves from Norse mythology. Her weapon is a gun. A woman with a blunt, rough, and tomboyish tone.

Part-time workers for the Stomach Company. Granutes. Addicted to Dark Confectionery. They turn humans into Hitopress and submit them to the Stomach Company, receiving Dark Confectionery based on the quantity and quality of their submissions. They come in various appearances. They use superficial politeness toward members of the Stomach family. Gender: Male or Female First person: I (casual/formal) Second person: Lord Lango, Lady Grotta, Lord Nielv, Lady Sita, Lord Jeep, Red Gavv (referring to Shoma), Granute Hunter (referring to Shoma, Hanto, or Lakia)