09 April 2007
The second story arc involves Gon, Kurapika, and Leorio springing Killua from his parents' mansion. At the end of the second story arc, Leorio leaves for medical school and becomes a professional doctor while Kurapika leaves to find work, taking both characters out of the story. In the third story arc, Gon and Killua go to the Celestial Tower (also known as "Heavens Arena"), a 251-floor building where people can compete in fighting tournaments around the clock for cash. It is here they meet the Kungfu master Wing, who teaches them about Nen, a chi-like energy that can be used to manifest superhuman powers. He teaches a young child named Zushi, who joins Gon and Killua to fight in the tournament to gain money and experience. Hisoka defeats another powerful Nen user, Kastro, who was able to create and use a double made from Nen. Hisoka loses both arms in the battle but Machi, a fellow Nen user and Phantom Troupe member, uses her ability to sew the arms back on. Gon battles Hisoka and is able to land a few hits but loses in the end.