Eikichi= is a cat. Kuwabara's cat to be precise. Kuwabara loves his cuddly pet so much that he would do anything to protect it no matter what the danger.

King Yama= is the ruler of Spirit World and the father of Koenma. King Yama leaves his son in charge while he takes off for a much needed vacation. Whoever said managing the world beyond was easy?

Okubo=One of Kuwabara's friends who is in his gang. Okubo is a respectable fighter in his own right. Unfortunately, his fighting also often gets him into trouble with his teachers at school. But despite the fact that his teachers have him pegged as a trouble-maker, Okubo is actually a very responsible young man. In addition to attending Sarayashiki Jr. High, Okubo works a part-time job to help support his siblings and his ailing mother.

Mr. Iwamoto=A teacher at Sarayashiki Junior High, Mr. Iwamoto considers Yusuke Urameshi and his trouble-making friends to be the scum of the earth. As such, he is determined to have these hopeless and unruly students permanently expelled before they can do irreparable harm to the school's all-important reputation. To this end, Iwamoto is willing to do whatever it takes, and will not hesitate to lie, cheat, or steal if he feels it will further the cause.

Mr. Takanaka=One of the head teachers at Sarayashiki Junior High, he sees a spark of good in Yusuke where his fellow teachers see only a worthless young punk. Mr. Takanaka is an honest and honorable man whose actions are motivated by a genuine concern for the well-being of his students. He is strict, but fair, and is the only teacher at the school that Yusuke respects.

Koto= is the emcee and referee of the Dark Tournament. All she loves more than her job is seeing how out of control the fights become. This bubbly girl lives for the heart stopping action of the competition and takes great pride in her work.

Juri=is the new referee of the Dark Tournament's Semi-Final round. She is a first time referee and relishes the fact that she knows the "rule book" backward and forward. Juri may share Koto's bubbly enthusiasm for competition and violence, but if the action ever turns a little rougher than expected, don't expect Juri to stick around!