Sai is a quiet boy, who hails from a small, rural town. Little did he know that his father was an ice demon, which means Sai is a half-breed (human/demon). His only friend was a girl named Karia, whom which leaves him later in life for fear of being killed by one of the countless demons that attack him. After Karia, the only person he has trusted since is the one he loves, Tanebi, a fire apparition.