Shoma, who comes from a different world, is saved by a boy named Hajime when he collapses from hunger. Shoma excitedly eats the snacks that Hajime gave him, but as soon as he does, Gochizo are born one after another.
Shoma, who has collapsed from hunger again, is helped by Sachika, who runs an anything and everything general store, and treats him to lunch and snacks.
By chance, Shoma meets a tough-looking man named Sujimoto and decides to help him with his work as he is asked.
Shoma mistakes the vegetables in the field for wildflowers and is caught by the owners of the field, Ryoji and his wife Mutsuko. After the misunderstanding is cleared up, Shoma is welcomed kindly by the couple.
Shoma collapsed from hunger and was saved by a mysterious monster. Is it a new Granute? Shoma wakes up and transforms into Gavv, but his movement was halted by an unexpected reaction: "The surgery was a success!" Who is this monster?
Shoma starts a new life at Sachika's "Happipare". Meanwhile, Suga has succeeded in developing an item that can transform a person into a Kamen Rider, and asks Hanto to try it out.
Gavv confronts Valen, the new Kamen Rider who defeated the Granute. Unaware of each other's true identities, the two begin to probe each other.
When Shoma asks Sachika why she is covered in paint, Sachika simply says that she made a mistake. Sachika, who does everything so dexterously, only replies that it was her own mistake. Shoma senses that there is a deeper reason, and bites his lip because he is helpless to help Sachika.
Shoma gets candy from children dressed in Halloween costumes. He is thrilled to taste the first candy that does not melt immediately, and new Gochizo are born one after another.
Hanto comes to "Hapipare" to ask for help in finding a missing cake store. Shoma hears about it and secretly sends the Gochizo to search for it.
Hanto has become a "suspect" in a romance scam. Called by Shoma and Sachika, Hanto goes to the coffee shop where he is supposed to meet a woman in order to catch the real culprit.
Hanto, who was rescued by Gavv, presses Gavv to reveal his true identity, saying it's not fair. Gavv is perplexed, but he has no choice but to release his transformation...!
Shoma is excited to see Sachika's prototype Buche de Noel before Christmas. He also challenges himself to bake a cake for Sachika.
Shoma manages to escape from the onslaught of Siita and Jiip, but is saved by Hanto and escapes the crisis, though covered in wounds.
Shoma is approached by Kani, the street musician Granute, begging that he wants to leave Stomach Inc. Shoma is gradually moved by Kani's remorse over the fact that he was wrong to attack people for the sake of the black market Dark Snacks...
Encouraged by Sachika to "apologize if you feel bad," Shoma heads off to rescue Hanto.
Shoma, searching for a missing high school student, discovers that other "kind and gentle" people have been disappearing one after another. Are such people the only ones being targeted by the Granute? If so, Sachika is in danger! Shoma rushes to Sachika's side, but...
Shoma and Hanto are troubled by the appearance of Kamen Rider Vram. While discussing countermeasures, Shoma is pressed by Hanto, who says, "There's something you're not telling me..."!
Shoma escapes the attack of Kamen Rider Vram and succeeds in rescuing Hanto, who has been knocked down, and begins a search for Takeshi, who has been turned into a Human Press and has not returned.
Shoma is reunited with Lage Nine, who harbors a grudge against the Stomach family for taking his brother's life. Shoma again tries to persuade Lage Nine to fight with him, and Lage Nine relents and sneaks into the Stomach factory to retrieve the Human Press.
When Hanto learns that Shoma is a member of the Stomach family, he is furious. However, he recalls Shoma's past actions and decides to listen to what Shoma has to say.
Shoma, who is attacking people, is a "Granute to be defeated" and Hanto challenges him to a fight, but he is somewhat unable to come to terms with the situation. Likewise, Sachika, who was told the truth about Shoma by Hanto, is trying to come up with her own answer.
Shoma joins forces with the reconciled Hanto to defeat Bitter Gavv. Shoma tells Hanto about the terrible memories that came back to him right after the battle...
Hanto begins to search for a Granute based on information from Kataro, but the Granute captures him.
Rakia starts working part-time at Hapipare on the recommendation of Shoma and Sachika. He is assigned to accompany a young boy who is going to meet a popular virtual streamer for the first time by introducing him to sweets.
Koji, who wants to take back Kabutodanshi, asks Rakia to accompany him again, but he refuses, saying that humans are no match for him. Koji gets angry and runs off on his own.
Shoma and Sachika find Hanto lying on the ground. Shoma leaves Hanto in the care of Dente and goes alone to Suga's laboratory to ask him what he has done to Hanto.
Hanto blames himself for the death of his mentor Shioya. Shoma finds Hanto in a state of exhaustion and tries to help him get back on his feet.
Shoma and Rakia participate in a basketball game as helpers. They successfully fulfill their role, but after the game, it is discovered that one of the players has disappeared. When Shoma and the others search the area around the venue, they find a suspicious man...!
Jiip appears before Gavv and Vram and introduces them to Liselle, the president's daughter and Jiip's marriage partner. They declare war on Shoma and Rakia and leave with wry smiles on their faces.