The day before the ceremony celebrating Yajima Stadium's completion, Nils Nielsen summons Sei Iori, Meijin Kawaguchi, and others for a showcase clash featuring the battle framework he has crafted. With everyone gathered again, Sei endeavors to display his enhanced Build Strike Cosmos for the event, yet he spots a glaring omission... At the same moment an unknown entity commandeers the arena's controls, trapping Sei and the rest inside. In a twist, a shadowy faction emerges, intent on confronting them with a Gunpla Battle in the heart of. For the ultimate showdown.
