Gon and Killua head to Heaven s Arena to train the higher a fighter advances there, the tougher their opponents become! Moving up quickly, the two friends soon meet Zushi, who tells them about the power of Nen, and they begin training under his mentor, Wing, to harness their potential. But the duo hits a wall on the 200th floor of the tower their Nen-using foes are strong, and soon Gon is injured. Will Gon and Killua gain the strength they need to advance further?