Team Dai-Gurren falls into a trap set by the third member of the Four Divine Generals, Guame. The Team is taken captive and stored underground to await execution. While digging an escape path, Simon finally understands Kamina's last words to him and after having a discussion with Guame, Nia finds out the reason why she was thrown away.

Team Dai-Gurren are now on their way to Beastmen's capital city, Teppelin but there's a vast ocean in their way. The only way for them to get across is for the Dai-Gurren to be modified, so while they wait everyone goes to chill out at the beach. Once preparations are complete, the Great Gurren Brigade begins their cruise, but there's an ambush waiting for them.

The last of the Divine Generals fall, and the city of Teppelin collapses, revealing a Gunman of gigantic proportions. Simon and Nia struggle to pass through it in order to confront her father, the Spiral King himself.

During the following seven years, a new civilization rises and prospers under Simon's leadership. However, these peaceful times come to end when the threat mentioned in Lordgenome's last words starts to reveal itself.

The members of Team Dai-Gurren make their preparations for the imminent war against the Anti-Spirals, but Rossiu is missing. However, when Kinon tells Simon about what he really intends to do, both start to look desperately for him.

After finally transforming their flagship into the Super Galactic Gurren-Lagann, Simon and his friends successfully fight back against the enemy. When their enemy starts to use their own memories and desires against them, Kamina reappears to help.

At last, Simon and Nia are reunited, and by combining the power of its members, Team Dai-Gurren creates the galaxy-sized Tengen Toppa Gurren-Lagann, and engage the Anti-Spiral threat in a decisive battle to determine the fate of the universe.