Chiyoko

Choyoko was a seemingly human girl of Japanese descent.

Biography
Chiyoko was first seen in an alliance with Axos, who had come to 21st century Tokyo to set up a fake company, which they called the Rising Sun Corporation. One of the corporation's "products" was a drink called "Goruda". They claimed was brain tonic, but which would transform those who drank it into Axons after a time. In it's public face as "Mr. Kin", Axos passed off Chiyoko as his ward and advisor.

When Axos encountered resistance from the Doctor and his allies, Chiyoko betrayed them, freeing the Doctor's companion, Amy Pond, and Major Harada of UNIT. When the Doctor defeated Axos, the dying gestalt claimed that Chiyoko had promised it Earth. Chiyoko replied by saying the deception was necessary "for a new life to begin." DWM: The Golden Ones

Chiyoko then somehow managed to travel to Paris, France, 1858, where she watched the Doctor and Amy depart. DWM: The Screams of Death