Tearju Lunatique

Tearju Lunatique is Yami (Golden Darkness) and Mea Kurosaki's creator, as she used her own cells in order to create Yami but didn't do the same for Mea. She is a genius in Universe Biotechnology and has been since she was a teenager. She takes the role of a klutzy (and beautiful) classroom teacher at Rito's school in the later chapters of Darkness. Tearju seems to be aware of Yami and tries to get close to her like before.

She is based on a character with the same name and appearance from Kentaro Yabuki's previous manga Black Cat. In that series, Tearju was also a scientist who created Eve (whom Golden Darkness was based on).