A part-time worker in the Criasu Corporation's Azababu branch office, she is a quiet and reserve gynoid who is extremely devoted to Ristle while using flying saucers as weapons.
Ruru infiltrates Hana's house while altering Sumire's memory to spy on the Cures, later stealing Homare's PreHeart on Papple's order to prevent the girl from helping her team. But Ruru returns the item to Homare after a change of heart, resulting in her being deactivated by Papple and taken away. She was reprogrammed and her memories were erased. She confronted the Cures with her robotic suit but she eventually regained her memories, reconciled with the Cures, and left Criasu.