Dayakka Littner is introduced as the capable and level-headed leader of Littner Village, a small underground human settlement. As the chief, he is responsible for the safety and well-being of his people, demonstrating strong leadership skills and a practical mindset from his first appearance. He shares a close friendship with Yoko Littner, a fellow villager and prominent fighter, and it is through her that he first meets the protagonists Kamina and Simon, whom he welcomes into his home.

Dayakka is characterized by his reliability, calm demeanor, and unshakeable composure, especially in contrast to the more boisterous and impulsive Kamina. These qualities make him a natural pillar of support for Team Dai-Gurren, the growing resistance force against the Beastmen. His motivations are rooted in the protection of his community and the broader cause of human freedom. After witnessing the victories of Kamina and Simon, he is inspired to take a more active role in the war, leading him to steal a Gunman from the Beastmen. He christens this machine the Dayakkaiser, which features a powerful cannon on its head and becomes his personal unit. He notably uses the Dayakkaiser to save Kamina and Simon from the massive enemy Gunman, the Dai-Gunzan.

His role within the group evolves significantly after the capture of the Dai-Gunzan, which is renamed the Dai-Gurren. Demonstrating his leadership and tactical acumen, Dayakka is appointed as the battleship's captain, a position that suits his responsible nature. He relinquishes piloting his Dayakkaiser to Kiyoh, a skilled fighter and one of the Black Siblings, so he can focus on commanding the ship from the bridge. In this capacity, he becomes a key strategic asset for Team Dai-Gurren, providing a steady and dependable presence in the heat of battle.

Dayakka's key relationships deepen over time. His friendship with Yoko remains a constant, and his working relationship with the more hot-headed Kittan Bachika becomes crucial for the team’s operations. The most significant development occurs after a seven-year time skip, following the defeat of the Spiral King. Dayakka has married Kiyoh, the sister of Kittan, and has started a family. He serves as the Minister of Food Affairs in the newly established Kamina City, a government position that again highlights his dependable and administrative skills.

However, when the new, cosmic threat of the Anti-Spirals emerges and endangers all of humanity, Dayakka does not hesitate to return to active duty. He resigns from his post and retakes his place at the helm, this time commanding the massive Arc-Gurren and later the even larger Super Galaxy Dai-Gurren. His development from village chief to battleship captain and government minister shows a man who consistently rises to meet the needs of his people, always prioritizing their safety. This is further emphasized when he is trapped in a multi-dimensional labyrinth by the Anti-Spiral; his idyllic vision is a simple life working in a bakery, showing his desire for peace, but he breaks free by reclaiming his core drill, reaffirming his fighting spirit.

Dayakka is also unique among the initial group of Gunmen pilots inspired by Kamina, as he is one of the few who survives to see the end of the war. In the final battle against the Anti-Spiral, he participates in the colossal formation of Tengen Toppa Gurren Lagann and performs a notable feat named the I-Got-The-Best-Wife-In-The-Universe Swing, where he uses an anchor to hurl the enemy's gigantic mecha away from Earth, showcasing his enduring strength and his pride in his family. His abilities are primarily those of a commander and tactician, though he is a competent Gunman pilot and later a highly effective battleship captain, guiding the largest vessels in humanity's fleet.