Jill Randou is the second daughter of Tatsuya and Reika Randou. She has four siblings: an elder sister named Reika and brothers Ryou, Jun, and Hiro. Jill pilots one of the specialized motorcycles that assembles into the arm components of the giant super robot Acrobunch. Each family member operates a separate vehicle, coordinating their efforts to form the complete Acrobunch during its transformation. Together, the Randou family embarks on a worldwide search for the legendary treasure of Quaschika, also known as Quetzalcoatl. They face persistent opposition in this quest from the subterranean Goblin Clan, who pursue the same treasure.