Koto (小兎), which literally translates to "Little Rabbit", is a demon girl that has been seen to be acting as the referee/commentator for both the Dark Tournament and the Demon World Tournament. She is later replaced by Juri as referee in both the semi-finals and the finals of the Dark Tournament, switching to mere commentary as she was suspected of miscounting in the match between Jin and Yusuke. She is also something of an idol in both the Human And Demon Worlds.
Koto is voiced by Ai Orikasa in the Japanese version, Amber Cotton in the English dub and Kata Csondor in Hungarian dub.
In the original Japanese, Koto is a bright and cheerful young lady who is admirably professional and devoted to her job, and is basically a good person who just happens to work for bad people. The English dub however, displays her as a vicious sadist, often giving her own commentary on how much she enjoys the pain and death she sees. In both versions, she has some standards as she disapproves of Bakken's attempts to keep Kurama's unconscious body in the ring.
Koto often seems overtly-amused in the suffering of the fighters at the Dark Tournament, but only when both contestants can fight, though she becomes easily frightened whenever there is a formidable attack such as the Dragon of the Darkness Flame, though not as much as Juri. In the Demon World Tournament her sadism is toned down a bit.
Koto is briefy the object of affection for Chu, whom she doesn't share feelings for. Ironically, in the Demon World Tournament, she seems upset over the fact that Chu fell for Natsume. She sometimes puts on a cute act, but is very shrewd and manages to get in jabs at Juri being a former cocktail waitress.
- The Funimation dub, in which Yusuke refers to Koto as a "fox girl", and her tail and ears resembling a fox cause most to believe Koto is a fox spirit. Some claim she may be a cat demon—she frequently meows in the manga, and in the Funimation dubbed anime she refers to her ears as "little cat ears" and is called a "kitten" by Bakken.
- Likely furthering the Australian stereotype, Chu calls her Sheila, as he does every other girl, which she seems to take a disliking to.