Tsukitou Kaguya

A mysterious Illuminator suddenly appeared in Rosecrown Beacon. She calls herself Lumina Fullmoon and claims to be from Highmoon Beacon, but has lost most of her memories. As a result, she has a strong curiosity about everything and occasionally says strange things.

Spoiler

This Lumina is just half the soul of the real Lumina Fullmoon in the Dreamland, the half of her that wishes to end the dream and face reality for some unknown purpose.