Alongside his identity's old partner Sou Yaguruma aka Another Kabuto, "Kageyama" seeks to prevent the Kamen Riders from stopping the meteors carrying the Worms so the Worms can invade Earth once again. Like the original Kageyama, this copy of him can transform into Kamen Rider PunchHopper.
After another meteor carrying the Worms crashed into Earth, Salis Worms emerged from it to attack and copy the appearances of humans. One of these Worms copied the appearance and memories of the deceased Shun Kageyama.
Kageyama attacked Kamen Rider Zi-O II and Kamen Rider Gatack while they were fighting a group of Worms. The two Riders manage to defeat him but Another Kabuto then shows up and escapes with PunchHopper.
The imitation Kageyama later approaches Sougo and Woz and asks for their help to save Sou Yaguruma from being an Another Rider. However, this was actually a trap set up to lure in Arata Kagami so they could kidnap him. With Kagami as his hostage, Kageyama tells the Riders he will only let Kagami go if the Riders give him the Ginga and Fourze Ridewatches, so they cannot stop the meteor carrying the Worms from crashing into Earth. However, Sougo and Woz manage to free Kagami and he transforms to fight Kageyama. Another Kabuto then shows up again to defend his "brother" from Gatack. PunchHopper and Another Kabuto fight Gatack and defeated him with a Rider Punch and Rider Kick, respectively. PunchHopper then takes the Ginga and Fourze Ridewatches with him, declaring that the meteorite cannot be stopped without those Watches.
However, as the two "brothers" are eating noodles and discussing what they will do after the meteor hits, Uhr appears before them. Not wanting the world to end, Uhr freezes time and takes the Ginga and Fourze Ridewatches to give to Sougo and Woz so that they can stop the meteor.
Another Kabuto and PunchHopper later fight Geiz and Woz at the top of a building. After the four force each other out of their transformations with their finishing moves, Kagami, Sougo and Tsukuyomi appear with the stolen Ridewatches. While Sougo and Woz head into space to stop the meteorite, Geiz Revive and Gatack to face off against PunchHopper and KickHopper. Geiz Revive manages to defeat PunchHopper with the power of Shippuu while Another Kabuto is defeated by Kagami. Yaguruma asks Kageyama to call him "brother" again, but the imitation Kageyama coldly tells Yaguruma that he was never "Kageyama" or his "brother" to begin with before reverting back to his original form as a Salis Worm and disintegrating.