Production

Gurren Lagann was first announced in July 2007 with Aniplex and Konami assisting Gainax in its making. Konami director Koichi Natsume suggested possibilities of the series getting multiple sequels. The series was directed by Hiroyuki Imaishi who was a fan of the mecha genre and ever since he started working he has wanted to work in a mecha series. After working on Re: Cutey Honey with Kazuki Nakajima, Imaishi appointed him as the writer, believing him to be the best choice. Imaishi was surprised with how much material Nakajima could condense into 27 episodes. Imaishi had finished writing the main storyline long before the reaching the end which facilitated the staff in making the episodes. According to Gainax president Hiroyuki Yamaga the series was in planning phases for a long time. Producer Yasuhiro Takeda used the time to research how would the characters live underground although this aspect is briefly used. Once the series started production, the team did not have much time to research materials.

In contrast to other popular series, Imaishi decided to include drills as the robot's main weapons despite its impact on the suspension of disbelief. Imaishi also wanted the series to only have robots. The robots were made organic so that they would be easier to animate. Nevertheless, animating episode 15 was challenging to the staff due to the several amount of shots it required. Its animator Sushio called himself the "super animator" for his work. Deciding the design of the Gurren Lagann was complicated since it was the basis for the other mechas appearing in the story.

In the making of the series, the team wanted to focus more on the underground life and Simon's imprisonment but their ideas could not be used. In the eighth episode Kamina dies in order to provide Simon character development and make him become the main character. Simon's development kept on going until the final arc when staff planned ideas to make him surpass Kamina. The ending was written to finalize Simon's growth and not leave signs of a sequel. The final had the pre-planned tragic event of Nia's death which left several staff members saddened. While the staff acknowledged how people were not satisfied with the sad conclusion, they noted that there were still issues that made her survival difficult for the characters. Once the series ended, Yamaga had the idea of releasing a film that retells the events of the series to expand the audience.