The stand-alone pilot OVA which was shown as part of the "Jump Super Anime Tour" of 1998.

[Source: Wikipedia]

Gon's father, long believed to be dead, is still alive and was once one of the greatest Hunters in existence. Gon believes he will be able to meet his father once he himself becomes a Hunter. However, before he can become one, he has to pass the Hunter Exam first, an exam made of numerous tasks and dangerous trials. Persevering and refusing to give up, Gon manages to reach the Hunter Exam, all the while keeping his innocent attitude. Throughout many of the tasks and trials of the Hunter Exam, Gon manages to make many unique friends. Kurapica, a sole survivor of his clan seeking revenge, Leorio, who wants to become a doctor, and Killua, a member of an infamous assassin family, all eventually join up with Gon in hopes of passing the exam together. Each of them have their own reasons for taking the exam, but will they manage to pass it alive? It will be no easy task, as the tasks and trials in the exam are not easy. Aside from worrying about dying from the exam itself, Gon and his friends also have to watch out for killers participating in the exam...

After reuniting with Gon and his friends, Kurapika explained to them the risks he bears because of his abilities. Believing that his target of revenge is no longer alive and the search for his fallen comrade's eyes could truly begin, Kurapika soon after receives a message informing him that all the Spiders still lived. After much discussion between his friends, Gon, Kurapika and company decided to hunt after the one Spider member who's ability could ultimately result in Kurapika's defeat and death. Based on the manga by Togashi Yoshihiro.

After the battle with the Spiders, the search for Ging continues as Gon and Killua decided to once again attempt to purchase the rare game "Greed Island". However, Gon came up with a better plan, which was to volunteer to complete the game for the billionaire who owned it. But some training must be done, as Gon and Killua's abilities are still at a developing stage and "Greed Island" is no simple game for anyone to play with. It is the infamous game that could easily lead to one's death. Based on the manga by Togashi Yoshihiro.

Continuing with their adventure at Greed Island, Gon and Killua train furiously under the guidance of Biscuit for better preparation at attempting the game. With their abilities vastly improving and the threat of player killers menacing Greed Island, Gon and company continue the game despite the dangers that they will face with the game activities and encounters with other players. Based on the manga by Togashi Yoshihiro.

A new adaptation of the manga series by Togashi Yoshihiro.

A Hunter is one who travels the world doing all sorts of dangerous tasks. From capturing criminals to searching deep within uncharted lands for any lost treasures. Gon is a young boy whose father disappeared long ago, being a Hunter. He believes if he could also follow his father's path, he could one day reunite with him.

After becoming 12, Gon leaves his home and takes on the task of entering the Hunter exam, notorious for its low success rate and high probability of death to become an official Hunter. He befriends the revenge-driven Kurapika, the doctor-to-be Leorio and the rebellious ex-assassin Killua in the exam, with their friendship prevailing throughout the many trials and threats they come upon taking on the dangerous career of a Hunter.

[Source: MyAnimeList]

Kurapika became a Hunter to take vengeance on the Class-A crime group Phantom Troupe who massacred his clan for their unique eyes. The eyes of the Kurta clan turn scarlet in times of anger or emotional agitation and are considered the most beautiful treasures in the world. Kurapika continues to pursue the Phantom Troupe but an unknown party has stolen his "scarlet eyes". With the help of Gon, Killua and Leorio, Kurapika' s life was saved. However, the Phantom Troupe shows up before them and blocks their way. The true identity of the one with the No.4 spider tattoo is about to be unveiled.

[Source: MyAnimeList]

The strongest Hunters that once existed in the Hunters Association were split into “light” and “dark”, and each walked down their respective paths. The “dark” side begins moving in order to massacre all Hunters! What actions will Gon take when the many crimes of Netero and the Hunters Association are unveiled...!?

[Source: Anime News Network]