Earth

Earth (地球, Chikyū) is the home world of Spiral Beings known as humans, a planet existing in the Milky way galaxy surrounded by nine planets, a sun, and a moon (which for 1000 years had been hidden away in an alternate space, the latter moon later revealed to be the Cathedral Terra, a Spiral battleship turned into a humanity annihilation system). Earth is divided into 4 regions, the Gekorn region, the Sekunga region, the Beharma region, and Kamina City

First Anti Spiral War
Earth inhabited a previous human civilization that thrived on Spiral Power and the Human genius, such as creating a human body in biological stasis, a self-replicating asexual food supply through the various animals that populated Earth, and humanoid warriors with the spliced genes of animals who could not emit Spiral Power. In the end, Humanity was suppressed by the Anti-Spirals, a group of alien beings bent on annihilating any, and all Spiral-life. The spiral and Anti-Spiral races began a war, and after years of endless bloodshed, a spiral warrior named Lordgenome was shown the truth of spiral power, the Spiral Nemesis, by the leader of the Anti-Spirals. After realizing this, Lordgenome compromised with the Anti-Spirals allowing Humankind to continue their existence as a small population allowed to survive within subterranean communities, abandoned his allies and fled back to Earth, commanding the armies of humanoid warriors now referred to as Beastmen to suppress humankind piloting Gunmen, and to keep them from rising to the stars again. The Anti-Spiral race after Lordgenome's return to Earth, replaced Earths natural moon and reconstructed his CathedralTerra into its new moon, a humanity annihilation system.

Before Beastmen War
Lordgenome became known as the Spiral King and separated his beastmen Human Eradication Army into four branches, each headed by a Supreme General modeled after the Spiral General system of antiquity. During his years ruling the surface, Lordgenome became bored, even using the nearby "Beauty village" full of woman to sexually satisfy him to no avail, becoming mentally and physically weary, a side effect of the very Spiral Power within him acting against him as more humans are starting to surface and challenging his armies.

Beastmen War
After a millennia, the group known as Team Dai-Gurren founded by Kamina, Boota and Simon the digger rose from the depths of Jeeha Village after the ceiling covering the village caved in by the gunmen Gozu attempting to pursue Yoko Littner. After destroying the gunmen with a Lagann found by Simon and skyrocketing to the surface. Cornered again by the other two gunmen, Simon, Kamina and Yoko where backed up by the people of Littner Village, giving them shelter and teaching them about the brutality of the surface, and the mysterious civilzation that once lived on it. Eventually gaining Gurren after a battle outside Littner Village, Simon and Kamina fought together against the commander of the Human Eradication Army Viral, combining into Gurren Lagann (Gunmen). Beginning their campaign to rebel against the beastmen and to find the point of return for Gurren, Simon and Kamina met the beastmen hunting Black Siblings, Kittan Bachika, Kiyoh Bachika, Kiyal Bachika, and Kinon Bachika, the citizens of Adai Village, Rossiu Adai, Darry Adai, and Gimmy Adai who later join Team Dai-Gurren after being told to leave to the "celestial lands" above by the village priest Magin. After being cornered and defeating the Hot Spring gunmen, Viral appears and reveals the presence of the Capital Teppelin and the Spiral King. To Simon and Kamina's dismay during the battle, the recall point for Gurren is revealed to be a giant walking fortress Dai-Gunzan belonging to Thymilph, one of the Four Supreme Generals. Kamina allows Simon to take command of Gurren Lagann, luring Dai-Gunzan to a cliff and using his drills to cause a rock slide, supposedly disabling Dai-Gunzan. Retreating for the time being, Simon and Kamina are surprised to see that a large group of reinforcements have come to back the group up. That night, the team begins preparing to take Dai-Gunzan using Simon's Lagann ability to combine with other mechas, but after seeing Kamina kiss Yoko, Simon's heart had been broken, ultimately leading to him being unable to fight properly until he was inspired to fight by Kamina, who ended up dying in the battle. The latter's death changed Simon profoundly, and Simon fell into a state of heavy depression, which forbade him from operating Lagann properly. Simon was however able to reconnect to the world again after meeting Nia Teppelin, unbeknownst to him or the crew, was the daughter of Lordgenome. After regaining his senses during a hostage situation by Guame the immovable, of the Four Supreme Generals, and believing in himself again, Simon was able to rescue Nia, and force Guame to retreat all the while broadcasting Team Dai-Gurren's victory to dozens of other human villages, becoming a symbol of hope for humanity. Team Dai-Gurren was able to defeat the Spiral Kings four generals, Thymilph the raging wave, Adiane the elegant, Cytomander the swift, and Guame the immovable, Viral's new body and finally face Lordgenome, revealing his Lazengann as a Gurren-Lagann type mech. As the battle came to an end, Lordgenome warned that when the world overflows with a million apes, the moon shall become Hell's messenger and completely destroy the world of the spiral. Lordgenome's lifeless body falls from the top of Teppelin as it begins to crash around Simon and Viral's mecha. As Gurren Lagann flies away safely with Simon, Nia, and Rossiu, the three look towards the toppled Teppelin as the sunrise marks the Seventh day of the attack on Teppelin, putting an end to the Spiral King's reign.

Second Anti Spiral War
As humanity begins to repopulate the surface, the humanity annihilation system is triggered by the birth of Kiyoh and Dayakka Littner's daughter Anne. On the same night that Anne is born, Nia's blood as the Anti-Spiral genes set within Lordgenomes offspring turns Nia into an Anti Spiral Scout who warns the people of Earth of the coming of the Anti Spirals. When the Anti Spiral Mugann appear and attack Kamina City, the mass produced Grapearl squadron are dispatched but are quickly deemed ineffective. Simon however uses Gurren Lagann's drill to dispatch the Mugann, however, due to his reckless attack, the Mugann dematerializes into dozens of reactive matter fragments, exploding on the city. This combined with a later attack after a now revived super computer of Lordgenome informs Rossiu about the Humanity Annihilation System, alongside Nia informing Simon of the same system, however broadcasting it, invoking despair into the hearts of the citizens, and Simon's second encounter with the Mugann, this time ordering Gimmy and Darry to shoot the fragments before they hit the city, deems Simon unfit to be the supreme commander of Earth, sentencing him to prison, the same prison used to sentence Viral after a prior incident involving a skirmish between him, Gimmy, and Darry while allowing dozens of citizens who felt more comfortable underground to go back to their natural homes. Outside, the worlds inhabitants are evacuated to underground shelters as Rossiu evacuates the people of Kamina City into a Dai-Gun nicknamed by Rossiu Arc-Gurren to leave Earths atmosphere and live in space for a year. After hearing the schematic of the moons true destructive force, Rossiu brought aboard animals alongside the citizens. Simon and Viral sit in prison, forced to observe the moons downfall after a fight in the shower room, are visited by Nia again, but is interrupted by Yoko who has left her teaching job to break out Simon, who then brings along Viral to fight with him in Gurren Lagann. Combined once again with the rest of team Dai-Gurren, the team assists Arc-Gurren an its Granpearl squad, reform the Cathedral Terra back to its original state, and bring back the Earths original moon from its alternate space. The team uses their new found perceptual teleportation to find Nia and the Anti-Spiral home world, only to be interfered with by a projection of Nia. After losing several members of Team Dai-Gurren, being beaten down into ultra dense space and destroying the Death Spiral Machine with Kittan's sacrifice, Team Dai-Gurren sees through the projection of Nia but are trapped in an Infinite Multiverse Labyrinth. As Simon relives his youth with an alternate Kamina, he realizes he has lost his Core Drill. To his surprise, another Kamina appears, giving him and the other members of Dai-Gurren to escape the Multi-dimensional labyrinth, using Laganns from the Death Spiral Machine to combine into Tengen Toppa Gurren Lagann to defeat the Anti-Spiral leader, homeworld, and Granzeboma. Team Dai-Gurren is able to defeat Granzeboma through the rest of Earth watching the fight, overwhelmingly increasing their spiral power, and allowing Lordgenome's new body to overload Lazengann and turn into a giant drill, allowing their power to overwhelm and attack the Anti Spiral leader. After finally defeating the Anti Spirals and freeing the rest of Spiral life, Simon and Nia go back home, marrying, only for her own life span as an Anti Spiral scout to finally fade. Simon departs Team Dai-Gurren, leaving his core drill to Gimmy, for the next generation to stop the Spiral Nemesis.

After Second Anti Spiral War
Human civilization has continued to evolve, communicating with the other Spiral worlds, and creating a Spiral Peace Conference, preparing the Super Galaxy Dai-Gurren and the Gurren Laganns of the new generation. From afar, Simon aids a boy in cracking a coconut, the two look up at the sky, watching the stars in the sky.