Shimada Aoi

A young woman of perhaps eighteen with large crimson eyes made larger by rimless glasses, round and prominent against high cheekbones. Her hair is lavender and pulled back into a complex, looping braid, secured with a generously sized bow of the same severe black as the majority of her costume, relieved only by touches of red and lavender. And said costume itself you can only call science-guca chic, with a poofy cravat disappearing beneath a double-breasted lab coat... and a skirt paired with stockings.

Which is most assuredly not proper lab gear, of course.

Aoi was the one who responded to Sabrina reaching out to schedule a meeting, and was eager to invite her over and speak with her.

Niko speculates that Riko created Tochimichi's body, one of a tripartite of "body, magic, soul".