Shoma is a human-Granute hybrid and former member of the Stomach Family who turned against them after they killed his human mother Michiru, including Hanto's mother Sae, when he discovered the truth behind his family's conspiracy. Upon arriving in the human world, he renames himself to honor the memory of his mother and vows to protect humanity from his former family and the Granutes who worked for them. Over the course of the series, he finds the only two family members who support him; his paternal granduncle Dente, who ultimately dies at the hands of Glotta, and his maternal uncle Masaru. Three months after the deaths of his siblings and Bocca Jaldak, Shoma starts developing to cure stranded former part-time Stomach employees from the Dark Treats' addictions, making said confection edible to both humans and Granutes alike without any side effects. Utilizing the Poppingummy Gochizo in conjunction with his modified belt-like organ, also known as the , attached to his abdomen, Shoma can transform into Kamen Rider Gavv . While transformed, he gains armor regeneration capabilities. He also wields the sword, which allows him to perform
feint attacks by launching Gochizo set in the vehicle-like projectile. His personal vehicle is the
ATV, which is summoned from the Vrocan Gochizo and can assume an alternate motorcycle form. • : An enhanced version of Poppingummy Form accessed from the Punchingummy Gochizo that equips Shoma with the gauntlet. This form first appears in the film
Kamen Rider Gotchard: The Future Daybreak. • : An auxiliary form accessed from the Fuwamallow Gochizo that grants bouncing and levitation capabilities. • : An enhanced version of Marumallow Form accessed from the Marumallow Gochizo that grants shapeshifting capabilities. • : An enhanced version of Chocodan Form accessed from the Chocodon Gochizo that grants the use of the to dual wield alongside the Chocodan Gun. • : An auxiliary form accessed from the Gurucan Gochizo that clads Shoma in a heatproof armored suit. In this form, he wields the double-barreled rotary cannon, which is reconfigured from the Vrocan Buggy. • : An enhanced version of Gurucan Form accessed from the Bakucan Gochizo that equips Shoma with the twin shoulder-mounted . • : An auxiliary form accessed from the Bushel Gochizo that grants chlorokinesis. In this form, Shoma wields the battle axe. • : An enhanced version of Poppingummy Form accessed from the Kickingummy and Punchingummy Gochizo that equips Shoma with the Range Kicking and Shuwa Punching at once. • : Shoma's super form accessed from the Blizzardsorbei Gochizo that grants cryokinesis and the use of varying abilities. He can also wield the Gavvwhipir if the Blizzardsorbei Gochizo was created by consuming
ice cream cake, allowing him to summon a pair of enhanced for combat assistance. However, Shoma can only use this form for a certain amount of time before the Blizzardsorbei Gochizo melts and forcefully cancels his transformation. • : An evolution of Poppingummy Form accessed from the Amazingummy Gochizo that grants thermokinesis. • : A special form accessed from the Kungfu Ramen Gochizo that grants proficiency in
Chinese martial arts. In this form, Shoma is equipped with a
buckler. This form appears exclusively in the Hyper Battle DVD special
Kamen Rider Gavv: Gourmet Snacks and Woo!-mai Wakamen!!. • : An enhanced version of Shield Snack Form accessed from the Choco Treasure Gochizo that grants the ability to morph Shoma's buckler into a
nunchaku. This form appears exclusively in the Hyper Battle DVD special
Kamen Rider Gavv: Gourmet Snacks and Woo!-mai Wakamen!!. • : A special form accessed from the Kin Choco Gochizo. In this form, Shoma dual wields a pair of handguns that resemble the Chocodan Gun. This form appears exclusively in the
Ishikawa Prefecture version of the stage show
Kamen Rider Gavv: Final Stage. • : A special form accessed from the Tako Sen Gochizo that grants a pair of cephalopod limbs. This form appears exclusively in the
Osaka Prefecture version of the stage show
Kamen Rider Gavv: Final Stage. • : A special form accessed from the Men Sen Gochizo. In this form, Shoma wields a
kanabō. This form appears exclusively in the
Fukuoka Prefecture version of the stage show
Kamen Rider Gavv: Final Stage. • : A special form accessed from the Uirou Gochizo. In this form, Shoma dual wields a pair of
tonfa. This form appears exclusively in the
Aichi Prefecture version of the stage show
Kamen Rider Gavv: Final Stage. • : A special form accessed from the Ningyo Gochizo. In this form, Shoma wields a
katana. This form appears exclusively in the
Tokyo version of the stage show
Kamen Rider Gavv: Final Stage. Later in the series, Shoma acquires the
jar-like device, which allows him to assume one of his two final forms. However, it can only function by absorbing 100 Gochizo and must be refilled after each use. • : Shoma's orange-colored final form accessed from the setting on the Gochipod that clads him in elasticized armor. In this form, he is equipped with the gauntlets, which increase his Granute strength to its fullest potential. • : Shoma's purple-colored final form accessed from the setting on the Gochipod that grants the ability to summon his preexisting forms' weapons. In this form, he is equipped with the sabatons, which increase his Granute speed to its fullest potential. Shoma is portrayed by . As a child, Shoma is portrayed by .
Hanto Karakida is a freelance writer investigating Shoma and the Granutes. After the final battle, he begins to publish the existence of Granutes and Dark Treats in response to the surviving former Stomach Inc.'s part-timers and Lizel Jaldak. • Bushel Form: An auxiliary form accessed from the Bushel Gochizo that grants similar capabilities as Shoma's version. • : An upgraded version of Chocodon Form accessed from the Chocold Gochizo that increases Hanto's fighting capabilities to its fullest potential. However, using the Chocold Gochizo to transform is progressively lethal. Later in the series, Hanto acquires his own Vrastum Gear, which allows him to assume the following forms: • : Hanto's final form accessed from the Frappeis Gochizo that grants cryokinesis and the use of the Chocodon Gun to dual wield alongside the Valen Buster. However, like Shoma's Blizzardsorbet Form, he can only use this form for a certain amount of time before the Frappeis Gochizo melts and forcefully cancels his transformation. • : A special form accessed from the Chocorappa Gochizo that grants ergokinesis. This form appears exclusively in the
V-Cinema Kamen Rider Gavv: Guilty Parfait. Hanto Karakida is portrayed by . As a child, Hanto is portrayed by .
Sachika Amane is the CEO of the jack of all trades shop where Shoma works and lives. Sachika Amane is portrayed by .
Rakia Amarga , code-named , is a
jellyfish-themed Granute miner who lost his younger brother Comel due to Dark Treats, leading the latter to be murdered by Glotta. Upon being hired by Lango as punishment for attempting to steal Dark Treats from a nearby available stall and secretly planning to destroy them, Rakia uses this opportunity to destroy Stomach Inc. from the inside while regretfully serving as their part-timer for the time being. He possesses the ability to generate energy tentacles that can paralyze his victims into euphoric states, allowing him to capture several humans all at once. When he was briefly promoted by Nyelv from part-timer to enforcer, before his true intention to destroy Stomach Inc. is exposed, Rakia gains the ability to transform into . One month after Suga's defeat, Rakia occupies the scientist's former hideout as his new permanent home. During the final battle, he decides to return to his home world and destroy the interdimensional gates that connect the two worlds while sending his Doppudding and Purujelly Gochizo to live in the human world. Utilizing the Doppudding Gochizo in conjunction with the belt, Rakia can transform into Kamen Rider Vram . While transformed, he retains his energy tentacles, which he can use as a weapon. • : Rakia's final form accessed from the Puddinte Gochizo that clads him in metallic armor and grants ferrokinesis. In this form, he wields the shield. • : A special form accessed from the Purujelly Noir Gochizo that grants umbrakinesis. This form appears exclusively in the web-exclusive special
Kamen Rider Vram: Route Stomach. Rakia Amarga is portrayed by . ==Recurring characters==