While visiting Heaven's Arena to cheer on their friend Zushi, Gon Freecss and Killua Zoldyck are caught up when masked attackers seize the tower and place a curse that seals the Nen of Hunter Association chairman Isaac Netero. The intruders wield On, a cursed force fed by pure hatred and opposed to Nen, and their leader has a buried grudge against Netero himself. This feature film stands apart from the TV story as Gon and Killua fight to free the chairman.