Upon arriving in the World of Agito, Yusuke is shocked that there are Grongi in the world which are being dealt with by Kamen Rider G3-X. He is further shocked when he sees an interview with Toko Yashiro, who is physically identical to the Ai Yashiro that died back in the World of Kuuga. Arriving at the police station, Yusuke offers to be the new user of the G3-X suit, but loses the position to Kaito. While this occurs, finding himself in a mailman outfit with a letter to Shouichi Ashikawa, Tsukasa and Natsumi find the man before they are attacked by what they think to be a Grongi. But during the fight, Tsukasa realizes he is fighting an Unknown, an Ant Lord called Formica Pedes. After destroying the Ant Lord, Shouichi refuses the letter before he and Tsukasa dodge an attack meant for him by a mysterious Unknown. Later that night, as Tsukasa reads the letter's contents, Yusuke leaves the Hikari Studio to remain in the World of Agito with Toko. The next day, Kaito is deployed as G3-X to take out the Grongi with Yusuke supporting him. During the fight, Kaito takes off the armor to finish the Grongi off as Diend, revealing that he only became G3-X for his own agenda. Though he destroys Me-Ginoga-De, Zu-Mebio-Da attempts to run off only to destroyed by a couple of Formica Pedes. While this occurs, Tsukasa finds Shouichi and offers protection, only to see him transform into Exceed Gills. Tsukasa attempts to restrain him as Kiva in Garulu Form. Gills, in pain of sensing the Ant Lords' attack, runs off and destroys them both before Yusuke's eyes. When Diend targets Gills, Decade tries to protect him, only to have his belt stolen by Gills with no defense against Diend's summoned Delta's Lucifer's Hammer finisher.[12]
アギトの世界。この世界でも未確認生命体と警察が戦っていた。クウガの世界で亡くなった八代刑事(佐藤寛子)と同じ姿と名前の女性を見つけたユウスケは、彼女を助けるためG3-Xの装着員に立候補する。一方の士は郵便局員として手紙を届けに芦河ショウイチ(山中聡)を訪ねるが、アンノウンに襲われる。
