Yu Kaito is a junior high student from Mushiyori City, where he enjoys a reputation as a prodigy only second behind Kurama.When former Spirit Detective Sensui began building a tunnel from their city to Demon World,he was one of the humans to gain psychic powers. However his curiosity got the best of him and he broke his own taboo costing him his soul, and forcing his fellow psychic friends Asato Kido and Mitsunari Yanagisawa to seek out the legendary psychic Genkai for help who restores Kaito's soul.The three are then used by Genkai to help prepare Yusuke Urameshi,Kuwabara,Hiei and Kurama for the upcoming challenges to come.The three meet with Yusuke outside his school, kidnapping the Spirit Detective who underestimated them believing them to be human. He is then the first challenge when Kurama,Kuwabara, Hiei and Botan arrive to rescue him.Using his territory he quickly captures the souls of Botan,Hiei and Kuwabara but it defeated by Kurama through trickery restoring their souls and costing him his own.Following Genkai's reveal at the end of the mansion, she once again restores Kaito's soul,with Kaito and his friends agreeing to help Yusuke and his friends search for the tunnel as it is their city in danger.
The next day Kaito is put on the same team with Kurama,Kuwabara and Botan to search the location of where the demon tunnel is being constructed. He was later part of the team that attacked the cave Sensui and his remaining fighters were using to complete the tunnel to Demon World.He participates as part of the group that plays against the Game Master in Goblin City, losing the trivia round to the boy after he knew the answers before the questions would appear. Following Kurama's defeat of the boy, he returned to guarding the entrance alongside Yana and Genkai. Following the group's defeat of Sensui he lives out a normal life, but only after Genkai warns him to never use his powers again.
Powers and Abilities
Kaito possess the ability to alter the rules in his territory. Inside all violence is forbidden, being blocked with a forcefield between the attacker and victim. He also possesses the ability to make certain words and letters Taboo, and if spoken costs the speaker their soul. Although it's important to note Kaito himself is governed by his own rules in his territory.