After fending off the Hoppers who disappeared into another dimensional rift, Yusuke reveals he was told of Decade by a mysterious man. When Ai and her task force go to investigate Mount Hitoki, a black mist begins to rise from within, signaling the revival of N-Gamio-Zeda. Resurrected by the dimensional chaos, he uses his miasma to convert humans into Grongi. While Yusuke saves Ai and takes her to the hospital, Tsukasa fights the Grongi alone. A dying Ai requests Yusuke to overcome his angst and fight to protect everyone's smiles, and so Kuuga and Decade work together to destroy the remaining Grongi. N-Gamio-Zeda, in a last effort, absorbs all the Grongi to power himself up, but he is ultimately overpowered by both Decade and Kuuga, who destroy him with a combo attack. After returning to the hospital, Yusuke finds that Ai has died and vows to honor her dying wish, setting off on his own journey with a mysterious white bat following him. Meanwhile, Tsukasa and Natsumi return to the photo studio, preparing to leave for the next world in their journey.[3]
クウガの世界。グロンギによるゲゲルを阻止したはずのディケイドだったが、目覚めるはずのない「究極の闇」―ン・ガミオ・ゼダが復活してしまう。どうやらクウガの世界も滅びの現象が起き始めているらしい。次々と現れるグロンギに一人立ち向かうディケイドだったが、なす術もなく追い込まれていく。
