Omi Kiriyama

桐山 臣
Omi is a second year student at Kouta039s school who is in fact a sickle weasel with the power to control the wind. Omi was once the bitter enemy of the Minamoto siblings. In the fourth volume of the novels he succeeds as the gang leader of the delinquents at his school. He hates the friendship between Kouta and his friends and does not speak much. In the anime he accidentally hurts Kouta who took a blow for Chizuru. Source: Wikipedia.