Kuwabara is bummed because Yukina had to return to the Ice World where she previously resided. Yusuke asks Hiei why he doesn't tell her that he is her brother. Hiei explains that he is a convicted felon and they are siblings through mother only, so he feels she would be better off not knowing. Yusuke asks him if the reason he got the Jagan Eye was to keep constant watch over her, but Hiei doesn't answer.
Meanwhile, back in the city, Yusuke is finally spending some quality time with Keiko, when a huge chunk of a building is blown up. He goes out to see what all the commotion is about. Then a masked man comes up to him on a motorcycle, and it is Toguro. It seems that after Yusuke and Kuwabara "defeated" the Toguro Brothers, Sakyo contacted them. They were working for him the whole time, and had staged their defeat to allow Sayko to win all of Tarukane's money.
They let the girl go since she wasn't even part of the plan. Toguro, however, is intrigued by Yusuke's power, and asks him if he will enter the Dark Tournament, a tournament thrown by greedy human mafia bosses and demons every year, for an all-out bloodfest. Yusuke declines, but Toguro brings up the other part. If he doesn't join, Toguro will kill Yusuke, and all of Yusuke's friends and family. He goes on to tell Yusuke that he was only fighting at 20% of his true strength when they battled before.
He demonstrates 40% of it by taking out an entire column of a parking garage. Needless to say, Yusuke is convinced, and rounds up Kuwabara, Hiei, and Kurama to be on his five-man team to enter the tournament. Yusuke goes off to train with Genkai, and Kuwabara trains with Kurama and Hiei for two years the reason those in charge set the deadline for that long is that the last tournament was a shit show with the worst fighters ever and they were incredibly weak so also during this time kurama Yusuke and Kuwabara manage to complete high school and graduate as they had every requirement so they graduated when they turned 16 now that school is out of the way they can focus on their training which is what they do they learn everything that Yusuke gave them Kuwabara learns the lightning element kurama learns the earth element and Hiei continues with the fire one thanks to Yusuke he was able to learn Byakko's Tiger Scream and Kuwabara was able to learn the Prism of 7 except that his max is 3 clones after much training he can do every training thing that Yusuke gave him with his clones as well.
Meanwhile Yusuke is mastering every techniuque that Byakko and Suzakku knew along with his other stuff not only that but Genkai teaches him how to finally create a demonic barrier so that he can block attacks from demon energy Yusuke also learns how to do everything there is about afterimages not only that but he finally masters Kazemaru's spirit blast technique once he masters everything that he picked up from the Saint Beasts Genkai puts him through everything that she did in canon before all of this training Genkai put the spirit cuffs on Yusuke in order to make him strong enough to handle the training Yusuke the final thing that he learns from Genkai is how to do the eye blast technique she used during her tournament after he gets to that level he calls boton after 1 year has passed upon his request Yusuke gets taken to spirit world Yusuke meets with Koenma and grabs Rando then lets him grab his final psychic who has lightning illusions barrier techniques and healing powers so Rando kills him absorbs his powers then Yusuke drops him in the same realm as where the Saint Beasts used to be genkai puts the spirit cuffs on him gives him everything that Yusuke gave the others except for one of each element she also made the monsters alot stronger with a spell going from the lowest class to mid-C class then she closed the door on him so that he can train she also put a seal on it that would make the gravity there 5 times that of earth she also messed with time where 1 year in the outside world equals 600 years down there.
Rando senses the changes but doesn't care he just keeps training and fighting until he becomes the strongest and after absorbing his 100th demon his body changes his hair turns deep purple his scars and veins turn the color of his hair used to be his body grows in size until he's the build of someone twice his size and his hieight grows by a few inches his skin turns to normal skin color the grey that used to be his skin color turns into pants his belt and shoes remain the same not only that but his aura is purple as well he continues training until he masters everything he was given it stops going up in levels at high C class he can live with that he just keeps training until one day about 6 months before the time is up he is joined first it's Kuwabara they train together for a month then next is Kurama then Hiei and finally Yusuke the final two months nobody trains at all Rando is brought before Yusuke and Genkai one day she removes the spirit cuffs from his body lets him get used to his power then teaches him how to control it properly after that Genkai says you will be the alternate on the team and the only reason Yusuke got you was because of how well you'd do in a tournament like this one he nods.
On the final day, Kuwabara, Hiei, and Kurama are waiting to board the ship to the island, and Yusuke hasn't shown up yet he arrives right before they leave, with the fifth man for their team, a short person with a white cloth wrapped around their head. he also arrives with Rando no one knows who the masked person is, but Yusuke assures them that the fifth fighter will be an incredible asset to their team having already fought Rando they don't question it.
The demons gather around a ship that is going to Hanging Neck Island, where the Dark Tournament is taking place. Yusuke arrives, and meets with the rest of his team. He introduces the fifth fighter for their team, known as the Masked Fighter. Team Urameshi boards the ship, and Yusuke is soon sleeping while the rest of the teammates eye the demons. The captain of the ship soon announces that only one team from this ship will be making it to the actual tournament, and that the ship is like a preliminary round.
A ring appears in the middle of the ship, and the captain instructs each team to send one fighter to the center, and they will compete in a battle royale. Whoever wins is going to compete in the Dark Tournament. Kuwabara and Hiei argue about who should go up, but the masked fighter silently walks up to the ring.
The monsters anticipate an easy kill, but as soon as the captain says start, the masked fighter uses a technique similar to Yusuke's, and beats all the demons in an instant. Everyone is surprised, and the team all realize why Yusuke chose this person to be their fifth fighter. The demons don't seem to want to accept a human team as the victor, however, and they gang up on Team Urameshi. Hiei slashes through them and Kurama lashes through them with his Rose Whip, using a technique called Rose Whip Thorn Wheel. The masked fighter knocks around a lot of them, and Kuwabara nails a few with his Spirit Sword.
One demon approaches the sleeping Yusuke, believing it will be easy to kill him in his sleep. Yusuke, however, mysteriously stands up and punches the demon hard in the face. The team realizes that Yusuke is still asleep. He shouts in his sleep, and Kuwabara recognizes what he said as a nickname for his mentor, Genkai. Kuwabara becomes suspicious that the masked fighter might actually be Genkai in disguise.
Back in Yusuke's town, Kuwabara's older sister, Shizuru, confront Botan about where Yusuke and Kuwabara went. She spills the story, and she demands that she take them to the Dark Tournament championship. Koenma and his blue ogre bodyguard also make plans to depart for Hanging Neck Island.
With all the opposing teams slaughtered, the ship docks at the port, and Team Urameshi is taken to a hotel. Inside their hotel room, they notice some unexpected visitors. One is a small kid, with star tattoos and a hat, and the other is a tall blond muscular man. They tell everyone that they will be their opponents tomorrow, and they are anxious to kill them. Then they exit, leaving Team Urameshi in wonder.