Gon is a young child with a lot of strength and even more determination. He uses this determination to acquire a nearly impossible-to-get game. Once he and his friend Killua start playing however they are sucked into another world entirely. One where they must acquire cards and train their strengths to even greater heights. However, this deviation from the main plot of the story takes what was previously a shonen anime and edges it much closer to the isekai genre. There is still plenty of fighting, plenty of friendship, and plenty of puzzles for the boys to solve, but the introduction of an isekai element was a bold and wonderfully executed move.
Hunter x Hunter follows the story of Gon Freecss as he seeks to reconnect with his lost/absent father. Along the way he learns that his dad was one of the creators of a mysterious game called Greed Island. He and Killua dedicate themselves to acquiring a copy, and once inside, they dedicate themselves to beating the game in the hopes that they will learn something about Ging Freecss.
The Game
Greed Island was an extremely exclusive game released only to hunters. There were only 100 copies made and with a nearly 6 billion dollar price tag. In order to enter the game one must be able to utilize Nen, a magic-like skill that is a requirement of the secret hunter exam. By the time Gon and Killua are able to acquire the game no one had yet beaten the game, and therefore many urban myths exist about the results of the endgame.
Once a player begins the game they are transported into the game, in reality to a remote island. If they die within the game they die in real life, but they are able to leave the game voluntarily or by winning it. All players in the game have two spells available to them through a ring, they can manifest a card book, and they can say “Gain” to turn a card into an object. The ultimate goal of the game is to collect all 100 specified cards in one's binder. The cards and spells only work inside the game, until Gon beats it and he is allowed to take three out with him.
An Isekai or Still Just A Shonen?
Isekai is defined as an anime where the character is transported to a strange world, if they come from a strange world and visit Earth that is considered a reverse isekai. Strictly sticking to this definition this arc of Hunter x Hunter is not an isekai since they are only teleported to a remote island. However, as far as any of the players know this is a strange world. There is unique magic, creatures that don’t exist anywhere else on the planet, and a complex set of world rules that apply only within the game.
Additionally to this shonen anime are technically considered action animes, meaning most isekai are also shonen, this arc included. Gon and Killua go on a dramatic training arc with a new teacher named Biksy, they fight monsters and gangs of other players, and they get through challenges through sheer force of will. But does the teleportation to another region of the world elevate this story from a simple shonen to isekai as well?
Until Gon and Killua prove otherwise everyone believes that players of Greed Island are transported to another realm, no one knows that it is just an island near Yorknew City. This combined with all of the previously mentioned factors strongly suggests that this still fits the criteria of an isekai anime.
Why is This Unusual
Most other isekai anime are just that, there is little if any time spent in the original worlds of the characters. Even Sword Art Online, one of the most popular isekai animes when one game is beaten the players simply join a new game, keeping real-world situations to a minimum. However, Hunter x Hunter does exactly the opposite, the isekai aspects of this anime are relegated exclusively to this arc. During this arc the boys spend all of their time in the game, there is no time spent in the rest of the world as isekai generally would have it. However, after the game is beaten the boys never return to it and there is very little reference to it even having existed. The boys simply go back to living life how they would have had the game not existed at all.
With eight current arcs in the show, Hunter x Hunter not very much time was spent in another world, leaving the main drive of this anime clearly a shonen anime. However, the creators made the bold choice to include just one isekai arc. This was perfectly executed and feels like a natural progression in Gon’s overall story. The choices that were made contrary to the rules of isekai, keeping them in the same world, blend the genre seamlessly into the rest of the story while still following the laws of the world that had been previously created.