Hina
Hina is the mother of Hiei and Yukina. Sometime in her life, she left the Glacial Village, where her kind live, and conceived children with a male. This resulted in the birth of twins, Hiei and Yukina. Although Yukina was born an Ice Apparition as her mother, Hiei was born a male, and part fire demon. The elders of the village deemed Hiei to be a danger to their society and declared that he must be destroyed. Rui, Hina’s closest friend, was instructed to drop Hiei from the Glacial Village into the depths of Demon World.
In the anime, Hina commited suicide shortly after Hiei was cast out. In the manga, however, it was said that she died shortly after giving birth to her children. Hina’s closest friend Rui was forced to be the one to throw Hiei into the depths of demon world.
Though not much of her was reveal one can assume that Hina was different from the other Ice Apparitions in the regards that she was willing to break their laws and find a man. More over it also shown that despite Hiei’s gender and dangerous power she still loved him deeply as she pleaded for them to spare him.