Shiiko used to be called "The Witch" and became a feared unicum (a MS ace), who scored over 100 kills against Zeon during the war.

She does not believe in the existence of Newtypes, but she herself is proven to be one. Shiiko dies in a competitive battle while using the new Gelgoog against the Red Gundam piloted by Shuji Ito. In her final moments she shares a Newtype Flash connection with Shuji and sees him and also her little son.