Pulled by the sprightly, pink-robed Botan, Yusuke enters a realm that is not quite normal -- the Spirit World. There, Yusuke meets Koenma, a 700 year-old ruler with the body of a toddler, pacifier and all! But there's no rom for laughs as Koenma gives Yusuke an ordeal to restore his life. Hatching a Spirit Beast!

Yusuke's three-day weekend is cut short when Botan delivers his next big case. Genkai, an aging psychic, will hold a contest to find a worthy apprentice to her powerful technique: the Spirit Wave. But an evil demon, Rando, plans to steal the technique and use it for mass destruction! Yusuke must go undercover and infiltrate Genkai's compound!

Yusuke returns from training with the great psychic Genkai, and not a moment too soon! Dreadful Makai Insects are invading his own city, part of a sinister scheme to flood the earth with demons! With Kuwabara at his side, Yusuke dives into a forbidden demon city. His target: four deadly creatures known as the Saint Beasts!

Yusuke, Kuwabara, Kurama and Hiei rush into the next part of the castle as they reach the final chamber where Suzaku awaits. Unknown to them Suzaku's master plan is being made - to capture Keiko.

Having rescued Yukina and defeated Toguro, Yusuke is spending some time with Keiko in the city. However, when a huge chunk of building is blown up, Yusuke sees Toguro, and they have a little chat. Turns out that Yusuke and Kuwabara really didn't defeat the Toguro brothers, as they were faking and working for Sakyo, and now Toguro wants Yusuke to enter a competition called the ""Dark Tournament"". Compiled of a group of greedy mafia warlords, Toguro convinces Yusuke, as Yusuke gathers Kurama, Hiei, and Kuwabara for his team, the gang sets out to compete in the tournament.

When he’s ambushed by a loose-cannon competitor, Yusuke learns that even quiet moments on Hanging-Neck Island are dangerous. Meanwhile, Hiei faces the consequences of his deadly dragon attack.

The doctor’s human experiments are clearly fighting against their will! As Yusuke prepares to put them out of their misery, the Masked Fighter intervenes and suggests a peculiar plan.

The match between Shishiwakamaru and Genkai begins. Genkai is very weak because she has given Yusuke her Spirit Wave power through the Spirit Wave Orb. Genkai however, has a great deal more wit than Shishi, and really nails him a few times. Shishi then decides to use his second item: the Banshee Shriek. Shishi is really excited beacause he thinks by using his sword to defeat Genkai, he'll become famous. He then shows off his power of the Chorus of a Thousand Skulls on the audience, killing many. Genkai is able to dodge it. After one more chorus, Shishi uses another of his new sword's power, the Death Cage. Genkai and Shishi are surrounded by a barrier of energy. Shishi goes in for the kill with an attack in which he puts his spirit energy into his sword when Genkai catches it and fires the Spirit Reflection Blast, blasting Shishi right through the cage.

With Karasu able to counter Yoko Kurama's attacks, the vicious member of Team Toguro is set to take the victory. Taking his own life into his hands, Kurama prepares to sacrifice his life energy in a final chance to defeat the demon. But with no life energy remaining, Kurama may stay down forever.

Yusuke reveals to Toguro that he has not been fighting at full power and removes the Spirit Cuffs, which reduce his power. Finally, a fully powered Yusuke launches an attack at his nemesis. But Toguro too has powered up to his top level and stares down Yusuke's most powerful Spirit Blast.

Kuwabara and the gang finally reach the room where Yusuke is being held captive. But Kido has one final game to play with the Spirit Detective. One of his friends is in fact an imposter, and Yusuke has only minutes to determine which one it is! With his decision made, Yusuke attacks!

Shinobu Sensui, the former Spirit Detective, is revealed to be the mastermind behind the plot to remove the barrier to Makai. Koemna discusses his fall into insanity with Yusuke's group.

Yusuke and his entourage have made it to Sensui's lair, but their battle to save the human race is just beginning. The opening to the Demon World is widening rapidly and shows no signs of slowing down. What's more, an old nemesis reveals his own master plan. His target, Kurama!

With no thought to their own safety, Kuwabara, Kurama, and Hiei charge deep into the tunnel in an effort to rid all worlds of Sensui forever. Meanwhile, King Yama's soldiers arrive to take Yusuke's body away to ensure he is never revived. As Koenma does his best to stop them, help arrives on the horizon in a very different form.

Control of Demon World is divided among three rulers: Raizen, Yomi and Mukuro. From his deathbed, Raizen has invited his descendant, Yusuke Urameshi, to return to Demon World to train under him for one climactic battle. Yusuke's first challenge is to defeat his ancestor. If he cannot defeat one of the three kings, how could he expect to stand up to the other two?!

Raizen's death has upset the balance of power in Demon World. Now it is up to Yusuke to prevent the threat of total upheaval. As Mukuro and Yomi prepare their next move, Yusuke arrives at a brilliant decision that just might preserve the peace. But at what cost?

As the fighters make their way through the main bracket of the Demon World Tournament, Yusuke Urameshi finds himself staring down Yomi. Both powerful warriors had their own reasons for entering, but one soon learns that he may not have any reason to continue. Which will be left standing when the dust settles?