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)

A new adaption of the manga of the same name 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.

Gon and Killua visit the Sky Arena to cheer Zushi on for Battle Olympia.  Two people who are excited about the reunion with their friends after a long time and the festival of martial arts.  However, a group of "darkness" plotting revenge on all hunters sneaks up on them??!!

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