Shinobu Sensui

Sensui begins his career with an intensely binary moral philosophy. Humans are innocent beings he must protect; demons are evil creatures whose destruction requires no moral hesitation. This absolute worldview makes him an effective Spirit Detective but leaves him poorly equipped to process evidence that contradicts it.

His encounter with Itsuki is one of the first challenges to that outlook. A demon asking to postpone death merely to watch a television finale strikes Sensui as so mundane and human that he spares him, gradually accepting that demons cannot all be classified as inherently evil.

Sensui is intelligent, patient and capable of planning on a scale far beyond most of Yusuke's opponents. His calm demeanor masks profound psychological fragmentation that becomes central to the Chapter Black conflict.

Sensui is one of the strongest human fighters in the series. His years as Spirit Detective give him mastery of martial arts, spiritual awareness and energy manipulation far beyond ordinary psychics.

His ultimate energy is Sacred Energy, an exceptionally refined form of spiritual power that normally requires decades of disciplined cultivation. Its purity and density place Sensui at a level capable of surviving deep within Demon World.

Sensui can manifest Sacred Energy as defensive and offensive armor. He is also a master of Resshuken, a martial-arts style that integrates spiritual energy into rapid close-range attacks.

Sensui possesses seven distinct personalities, several of which have different behavioral traits and combat specialties. Minoru handles much of the planning, while the violent Kazuya uses an energy weapon formed from his arm.

Sensui's history as Spirit Detective shapes the entire Chapter Black Saga. During his career, he encounters Itsuki and gradually learns that demons are more morally complex than he had assumed.

His worldview finally collapses when he witnesses the Feast of Human Vices, where wealthy humans torture captured demons for entertainment. Unable to reconcile the atrocity with his belief in human goodness, Sensui massacres those present and later develops multiple personalities.

Years later, he organizes the Sensui Seven and works to expand the tunnel connecting Human World and Demon World. Although the plan appears intended to unleash powerful demons upon humanity, Sensui's deeper motivation is personal: terminally ill, he wants to enter Demon World and be killed there as a form of atonement for the demons he slaughtered as Spirit Detective.

Sensui defeats Yusuke and crosses into Demon World, where their battle resumes after Yusuke's Mazoku heritage awakens. Raizen eventually takes control of Yusuke's body and overwhelms Sensui.

Itsuki is Sensui's oldest companion and closest confidant. Their relationship begins during Sensui's Spirit Detective career and becomes an intense, deeply unhealthy mutual attachment.

Yusuke Urameshi is Sensui's successor as Spirit Detective and ultimately the central opponent to his plan.

Koenma was Sensui's superior during his service to Spirit World and later carries enormous guilt over what happened to him.

Kazuma Kuwabara possesses the Dimension Sword, making him essential to opening the final barrier to Demon World.

Kaname Hagiri, Minoru Kamiya, Kiyoshi Mitarai, Tsukihito Amanuma and Sadao Makihara are psychics recruited into Sensui's group.

Kurama and Hiei pursue Sensui into Demon World after the tunnel opens.