Darry Adai hails from Addai Village, an isolated underground settlement whose inhabitants revered surface-operating mechas, called Gunmen, as deities. The village enforced strict population control through a lottery system exiling individuals when residents exceeded fifty. Father Magin, the community's leader, manipulated this lottery to exile Darry and Gimmy Adai, securing the village's survival. Rossiu, recognizing their peril, voluntarily departed with the children as they joined Team Gurren's battle against the Spiral King.

After humanity's victory over the Spiral King and a seven-year timeskip, Darry reappears as an adolescent. During this period of accelerated technological advancement, humanity reverse-engineered Gunmen technology to develop mass-production mechas named Grapearls, based on research from Gurren Lagann. Darry pilots a distinct Grapearl model alongside Gimmy, cementing her role within the military forces protecting the surface world and Kamina City. This position places her among the defenders confronting the new threat of the Anti-Spiral and their faceless mechas, the Mugann, amid the events preceding the Moon's descent.