Kiyoshi Mitarai

Mitarai is withdrawn, insecure and deeply pessimistic about other people. Years of bullying leave him receptive to the argument that humanity is fundamentally cruel.

Viewing the Black Chapter intensifies this outlook. Sensui's ideology gives Mitarai a framework through which his personal suffering appears to represent something universal rather than simply the behavior of individual tormentors.

Despite this bitterness, Mitarai is not naturally remorseless. His conscience and fear distinguish him from several of Sensui's more committed followers, leaving him capable of reconsidering what he has agreed to support.

Mitarai's Territory manifests through water mixed with his own blood. By adding blood to water, he can create aquatic monsters whose forms and properties he controls.

Victims swallowed by these constructs become trapped inside his Territory. Conventional escape is extremely difficult because the enclosed space functions according to the rules of Mitarai's psychic power rather than ordinary physical conditions.

His creations can also move and attack independently under his direction. The effectiveness of the ability makes Mitarai dangerous even though he lacks the hand-to-hand experience of Yusuke's group.

Mitarai first becomes directly involved with Kuwabara when he attacks Kuwabara's school friends after a concert. He traps Kirishima, Okubo and Sawamura inside his water creatures.

The crisis forces Kuwabara's dormant dimensional ability to emerge. Kuwabara manifests the Dimension Sword, cutting through Mitarai's Territory and freeing his friends.

After being defeated, Mitarai reveals Sensui's plan and turns against the group he had joined. He becomes an ally to Yusuke's side, providing crucial information about the tunnel and the psychics protecting it.

His experience also helps expose how Sensui recruits vulnerable humans by showing them carefully selected evidence of mankind's cruelty.

Shinobu Sensui recruits Mitarai after his exposure to the Black Chapter and uses his disillusionment with humanity.

Itsuki is part of the same conspiracy to open the tunnel to Demon World.

Kazuma Kuwabara defeats Mitarai and ultimately becomes one of the people whose actions help shift Mitarai away from Sensui's ideology.

Kirishima, Okubo and Sawamura are the friends of Kuwabara whom Mitarai traps inside his Territory.

Yusuke Urameshi accepts Mitarai's information after he abandons Sensui's side.

Kurama and Hiei also become part of the group acting on the intelligence Mitarai provides.