Aino

was a servant of the emperor of the Land of So, Tenji and served as Kaguya Ōtsutsuki's personal attendant when she first appeared on Earth.

Background
Aino lived a full millennium before the start of the main story. She worked as an the attendant of the emperor of the Land of So. After arriving on Earth, Kaguya was made Tenji's concubine and ordered Aino to serve as Kaguya's personal attendant.