The Hokage Ninja:
Reina was Kurei's mother. She was an arrogant, proud woman who was willing to take advantage of the fact that her son would be the next leader of the Hokage. Because of this, the other women of the clan had little respect for her. However, she truly loved her son, and was willing to have Recca killed to ensure Kurei's future.
Ohka was the leader of the Hokage Ninja, father to both Kurei and Recca. He was a Flame Master who died unable to protect his loved ones, and consequently became Resshin, the leader of the Ryu (Flame Dragons). However, he never permanently lent his powers to either Recca or Kurei.
Kagero was Ohka's wife, after Reina. Kurei and Reina hated her because she had been Recca's mother, even though it was because of her pleas that Kurei's life was spared. She sent Kurei and Recca into the future with her time-manipulation.
Recca was the second son of Ohka, and was born with a Flame power. Because of this, Kurei and his mother were banished to the outskirts of the village and the other children would beat Kurei up because he was no longer important. Kurei attempted to kill him one night, but only succeeded in scarring Recca's cheek. He, Kagero (now known as Kage Houshi), and Kurei are the only survivors of the Hokage Ninja in the present-day.
His Adopted Parents and Friends
Mori Tsukino found Kurei when he was lost, and took him in. Kurei loved her very much, but she was banished to a mountain cottage and kept prisoner there. A small bomb was implanted inside her to ensure Kurei's cooperation.
Mori Kouran is a powerful underworld leader. Though married to Tsukino, he only cares about his money, his power, and keeping them forever. Kurei was adopted by his wife, but Mori Kouran turned him into his own killing machine. It was Mori Kouran who played a very large part in making Kurei the cold, unfeeling, and powerful villain he became.
Kurenai was Kurei's girlfriend. She loved roses. Although Mori Kouran had trained Kurei to be unfeeling, she broke through and Kurei fell in love with her. Because of this weakness, Mori Kouran detonated her bomb which had been implanted inside her. Kurei was devastated, and had his Flame assume her shape.
The Members of his Uruha Jushin Shu:
Raiha is a purple-haired ninja who seems to be Kurei's right-hand man. He seems to have a pleasant personality, but this does not make him any less dangerous of a fighter. He was able to make it to the semifinals of the Ura Butou Satsujin without ever using his madogou. Then, he withdrew out of respect before fighting Kurei's team. He remains loyal to Kurei after the tournament ends.
Neon is in love with Kurei, and enters into a relationship with him at the end of the Ura Butou Satsujin. After seeing Kurenai's fate, and the effect it had on Kurei, she wished to protect him. She went to Raiha and asked how to join his elite forces. It was hard training, but she became one of his top fighters. It was she who saved Kurei from death after Mori Kouran turned on him at the end of the tournament.
Joker is an arrogant guy from Osaka. He has long braids and fangs and is very powerful. Kind of like an adult version of Koganei... *g* He remains loyal to Kurei during and after the Ura Butou Satsujin.
Genjuro taught Kurei the "Genjutso Wakemi" technique (the "Illusion Technique Offspring").Although he pretended to be loyal to Kurei, to save his own life after one of their fights, he expressed traitorous intentions during the Ura Butou Satsujin, and was disposed of by Neon.
Noroi, nicknamed "Noroi the Butcher", was actually a dead body animated by a mask. He could not feel pain, but was defeated by Domon during the tournament. The spirit which animated the mask was released, and Noroi ceased to exist.
Kai was an inheritor of the Hyomon Ken, although a backup for Mikagami. He pretended to have killed Mikagami's sister, but later explained that it was actually their master who had done so. He seems to have been loyal to Kurei, but committed suicide after he confronted Mikagami in the tournament.
Jisho was killed off by Magensha's team before he had a chance to confront the Hokage in the Ura Butou Satsujin. He appears to have been relatively loyal to Kurei.
Mikoto was a member of the Ura Jushin Shu, and seems to have been a girl after Mori Kouran's own heart. She has no hesitations about killing things, for whatever reason, and is willing to fight dirty in the process. While it was never shown that she was disloyal towards Kurei, it is doubtful he had much respect for her.
Rassen- Appears in the manga, after the tournament, but not in the anime.