On their way to Teppelin Team Dai-Gurren stumbles upon a vast ocean and must wait before crossing it. While the rest of the group play at the beach, Yoko starts to feel uneasy about Nia. After preparations are complete, Team Dai-Gurren begins their sea cruise, oblivious to the fact that an ambush is underway by Adiane and Viral.

At last, Team Dai-Gurren arrives at the outskirts of Teppelin, but before aiming to the city, they must face a combined full-scale attack of Cytomander and Guame's forces.