Gon and Killua arrive at the Heavens Arena and begin to work their way up, making a new friend, Zushi, who is trained in the martial arts.

While working to understand Nen and Ren, Gon and Killua run into a familiar acquaintance.

After reaching the 200th floor, Gon and Killua run into Hisoka's barrier of Nen. They ask Wing to use the violent method for activating their Nen potential. As the deadline for registration draws near, they begin training in one of the four major principles of Nen, Ten.

Gon faces the Nen user Gido in his first 200s Heavens Arena match. Gon uses Ten to protect himself, but he soon finds himself on the defense against Gido's Dancing Tops. As Gon desperately tries to find a way to fight back, he makes a bold decision...

A month has passed since Gon was seriously injured, and Hisoka and Kastro are about to fight in Heavens Arena. Kastro was able to knock Hisoka down in the past and sounds very confident in his interview. Hisoka appears unperturbed by the upcoming fight.

Kastro has used his ability to create a clone of himself with Nen to sever Hisoka's arm and take an advantage in the fight. However, despite losing both arms, Hisoka appears to be perfectly calm. Kastro loses his cool and attacks Hisoka.

After two months, Gon and Killua are finally allowed to practice Nen again. That's when Gido, Sadaso, and Riehlvelt appear before them and tell them to fight them in the arena. Gon and Killua refuse, but Killua finds Sadaso's behavior to be very suspicious.

Gon has fights against Gido and Riehlvelt coming up. He's still mad about what they did to Zushi. Gon is able to withstand Gido's attacks and overwhelm him in battle. This causes Hisoka to smile.

Gon and Killua begin training in Hatsu, the culmination of everything they've learned about Nen. And finally, Gon challenges Hisoka to return the favor from the Hunter Exam.

After landing a punch on Hisoka, Gon returns the tag from the Hunter Exam. Hisoka is ecstatic to see Gon's development and uses his own Nen to attack. Gon is scared, but he recklessly continues to attack! Will he emerge victorious.

After learning Nen and becoming a true Hunter, Gon returns to Whale Island with Killua. When he arrives, Mito has a box for him. She was told by Ging to give this box to Gon once he became a Hunter. However, it appears that the box cannot be opened.

Gon and Killua have begun to listen to the cassette tape left behind by Ging in anticipation of Gon becoming a Hunter.