Isaac Netero is the chairman of the Hunter Association. Decades ago he sealed away Jed, a Hunter who had mastered the use of On, the dark "shadow" of Nen. Now On users have reappeared at the Heaven's Arena "Battle Olympia" tournament. For Netero, this is the last mission: to protect the Association and the world from a threat driven by hatred and the thirst for revenge. And he's going to need all the help he can get in order to succeed.
The stand-alone pilot OVA which was shown as part of the "Jump Super Anime Tour" of 1998. Shortly before the TV series, a summary is presented of the story of Gon who wants to become a hunter and the friends he makes in the process.
When the Spirit World is flooded due to an unusual rainfall which overflows the River Sanzu (aka the River Styx), Lord Koenma senses an extremely powerful enemy. He entrusts Death God Botan, to deliver to Spirit Detective Yusuke, a mysterious item which must be protected from the invading enemy. However, by the time Botan finds Yusuke, she's too weak to explain the situation. Yusuke and his friends are left in the dark about the new enemy, but not for long. Soon it is a battle for Earth between mere Spirit Detectives and the almighty king of the Netherworld.
Two recap specials that focus on Team Urameshi's matches in the Dark Tournament and four separate volumes focusing around one of the main characters; Yusuke, Kurama, Hiei, or Kuwabara.
While vacationing, Koenma is kidnapped by a pair of demons known as Koashura and Garuga, who demand the possession of Lord Enma's coveted "Golden Seal." Botan finds Yusuke Urameshi and Kazuma Kuwabara on their summer vacation as well, and asks for their assistance in Koenma's rescue.
