A homunculus artificial human a living weapon created by Hibiki. Hibiki created her for Yutsuko who attempted to replace her dead child with an homunculus but only created unstable bloblike creatures which disappeared after three days. After some work Hibiki and Shirotsuki create a homunculus. While at first very bratty and naughty she later gets along with Hibiki and the two develop a warm relationship. However Shiraasan is still an incomplete being and her life is placed in risk. Later her existence is stabilized and she becomes something of a sisterdaughter to Hibiki. She lives with Hibiki and often becomes involved in her mishaps along with Ahito. As a homunculus Shiraasan is a living weapon. Her power allows her to materialize guns and other such weapons. When her powers are used her pupils narrow. However because she is a magical existence overusing her powers can cause her to disappear.