Simon and his "brother" Kamina live in the underground Jidah Village. While Simon spends his time digging around for treasures (something the village appreciates), Kamina has a bad reputation as a troublemaker and because of his dream of reaching the surface.

In one of his excavations Simon finds a small drill-shaped key and, further down, a "face". As he's about to show his find to Kamina the village is attacked by a giant robot called Ganmen, followed by the gunslinging girl Yoko. Together, the three of them activate the "face" that Simon found and use it to fight the threat and blast to the surface... Where more trouble awaits them.

From there on, Simon Kamina and Yoko decide to travel the surface of the world, discover new places, and fight against the Ganmen and their beast-men pilots. One thing is for sure: with Simon's Lagann and Kamina's Gurren at their side, their lives just got a whole lot more exciting! Written by Gainax and Kazuki Nakajima with art by Kotaro Mori, so far only 1 tankoubon has been relesaed. Book 2 is due in March 2008. There are multiple Tengen Toppa Gurren Lagann manga being released currently, some of which are hentai. The official series is published in Japan by Dengeki Comics.