The Lights in the Sky are Stars

The Anti-Spiral probes Nia for the root of her defiance, dismissing her as a virtual lifeform spliced into a spiral race's genome to wake as a messenger and nothing more. She promises that Simon will come, and her ring blazes green as a drill smashes her free, the Gurren Lagann behind it; Simon wraps her in his coat, his promise kept. Thirteen more drills deliver the entire crew, and Simon brushes aside the enemy's disbelief that anyone escapes the Multiverse Labyrinth. Machine nests within machine, every member piloting a Lagann pulled out of the Galactic Spiral Abyss, and Tengen Toppa Gurren Lagann takes form astride a spiral of stars. The Anti-Spiral answers with the Granzeboma to fight on even ground, while Lordgenome, restored to a full body, tells Nia he cannot claim to face her as a father, yet believes she has done well.

The duel of titans opens badly. Yoko conjures a rifle the size of a mega galaxy and strikes a sphere between the enemy's horns, the Anti-Spiral homeworld itself, but the foe hurls whole galaxies like shuriken while recounting how it sealed its own bodies and homeworld away as proof of its resolve to guard the universe. The rifle is sliced apart, Viral's blades shatter, and the Granzeboma batters Tengen Toppa Gurren Lagann through galaxy after galaxy. The clash rips open a space-time bypass to Earth, and help flows backward through it: Dayakka snares the enemy with dimensional anchors and a swing dedicated to the best wife in the universe, and Attenborough's probability-alteration missiles cancel its chances of blocking. Simon proclaims that the tomorrow they fight for is one they chose out of infinite universes, and that they will stop the Spiral Nemesis themselves. Enraged, the Anti-Spiral rams two galaxies together to charge the Infinity Big Bang Storm, energy on the scale of creation; Lazengann surges from the giant's mouth, and Lordgenome, telling Nia to spare her tears, absorbs the blast through quantum breakdown and converts all of it into a tremendous drill for Simon.

Armed with that gift, the crew finally wounds the regenerating Granzeboma. Simon calls their strength evolution measured minute by minute, then turns the enemy's talk of limits around: a race that walled itself into a closed universe and cages other life has met nobody's limit but its own. The last charge becomes a relay, each machine bursting from the mouth of the larger one as the enemy pins them in turn, until Viral cannonballs the bare Lagann at the homeworld. Tentacles shear away its limbs and Simon's glasses shatter, but the Lagann Impact bores clean through the Anti-Spiral, whose dying words ask Simon to protect the universe. He answers that humanity is not stupid enough to destroy it.

The pocket dimension collapses, the fleet returns home, and freed spiral races call in with messages of joy. A week later Rossiu officiates the wedding of Simon and Nia, but moments after the kiss she begins dissolving; with the Anti-Spiral destroyed, nothing sustains her. They trade final declarations of love, and only her ring remains. Simon refuses to spend spiral power raising the dead, arguing the departed would crowd the next generation, hands the Core Drill to Gimmy, leaves government to Rossiu, and walks toward the horizon carrying the ring as plain Simon the digger.

Twenty years on, President Rossiu and an aging Leeron prepare the first Galactic Spiral Peace Conference. Yoko, going by Yomako again, is principal of her island school, and her former student Nakim flies with the Grapearl squadron. Gimmy and Darry pilot the Gurren Lagann, Viral commands the Super Galaxy Dai-Gurren as Earth's envoy, seven swords stand beside Kamina's grave for the fallen, and a flowered cross holds Nia's ring. On a beach that night, a weathered drifter shows a boy how to work a drill gently, shrugging off the question of who he is. As the fleet streaks skyward, Boota rides the old man's shoulder, and the aged Simon calls the lights above stars where their spiral cousins wait.

Tengen Toppa Gurren Lagann is created and lost in the same battle, the Granzeboma makes its only appearance, and the Anti-Spiral dies to the Lagann Impact. Lordgenome sacrifices himself a second and final time converting the Infinity Big Bang Storm into spiral power.

Simon and Nia marry, and Nia fades from existence moments later. Simon hands Gimmy the Core Drill and retires into anonymity, and the epilogue jumps twenty years to an Earth in contact with spiral races across the galaxy, working to prevent the Spiral Nemesis.

The Japanese title, Ten no Hikari wa Subete Hoshi, corresponds to the English broadcast title The Lights in the Sky are Stars. Japan aired the finale on September 30, 2007, with the English broadcast on November 10, 2008. It follows Episode 26 and closes the series.

Gainax stopped at twenty-seven episodes with the production budget nearly spent, and the staff felt a purely happy ending would not have worked. Tengen Toppa Gurren Lagann set the super robot genre's size record, a mark the studio itself later broke with a Super Tengen Toppa upgrade. Breaking with the preceding episodes, the eyecatches drop the usual Row Row Fight the Power music, the epilogue reveals Simon as the narrator of the whole series, and the second film retells this ending with substantial changes, including Simon keeping Nia's ring.