Sakuya is Eureka's predecessor, sporting lavender hair. Because she was a girl of mysterious power, the religious authority of Vodarac thought she was some sort of messiah and placed her in the central part of the temple. They banned any disciple from speaking to her, and allowed very few select disciples to care for her in a highly reverent, if sterile, manner.
For forty years since her initial appearance, she had no significant contact with anyone. This changes when Norb is assigned to care for her. Norb and Sakuya fell in love. Though they tried to keep it secret at first, a priest catches them embracing and assumes it to be a sign that Sakuya has chosen someone to travel to the Scub Coral with. They are hurriedly sent to cross the zone, but fail in the attempt. Both Sakuya and Norb suffer some sort of physical deformation but Sakuya is by far the most affected since she is turned into a giant lotus flower.
After her transformation, Sakuya erects a barrier around temple city, blocking out everything, including trapar (which is now poisonous to her). Norb eventually brings the Gekkostate to meet Sakuya, since her help is needed to get Renton and Eureka past the Great Wall successfully. Eureka meets with Sakuya in another reality in the form of a library. There they talk about what they learned and how Sakuya and Norb first met. After sending Eureka back, she and Norb stay in the temple to disable the barrier around it and use the energy to help Eureka and Renton pass through the Great Wall. For Sakuya and Norb, they were taken to the Zone where they could be together while Renton and Eureka discovered Earth.
