Kororo

Kororo (Corey in the English anime) is a Koropokkuru, a tiny spirit people and the guardian ghost of Usui Horokeu. She is a nature spirit and can, therefore, take solid form without being placed in a medium and is able to control ice on her own. People who meet her are often smitten by her cuteness. Kororo was once a human girl, named Kurobe Tamiko (黒部 民子,"Kurobe Tamago") whose family moved to Hokkaido because of her father's work. She was nicknamed "Damuko" because her father was constructing a dam that would destroy everything in the area, something that led her to be shunned. In school, she tried to befriend Usui Horokeu. At first, he rejected her, but because they were alike as both of them were lonely they became friends. Due to the dam, the Ainu Tribe Elder forbade Horohoro to see her and after her family demolished his favorite Fuki Field, he decided not to talk to her.[1] Half a year later Tamiko following Horohoro into the mountains where she had an accident and eventually froze to death. The Koropokkuru tried to guide her soul to the afterlife but she refused, wanting to know the reason why Horohoro ignored her. Gororo appeared saying that the only way to stay on this plane was to become a nature spirit like them, and protect the lands and its people, which Tamiko accepted. While Horohoro fought with Kalim of the Ten Patch Officiants, Kalim called Horohoro by his real name to make him reveal his true self. Angered, Horohoro revealed the events that happened between him and Damuko which made Kororo take her true form as Kurobe Tamiko. She explained what happened to her and that Gororo told her that once becoming a Koropokkuru she would stay in that form until her master's "Ice Thawed" where she returns to her true form once. As she turned back to her original form, Horohoro hugged and apologized to her