Gao's class is introduced to a new substitute teacher: the eccentric Elf Kabala, who is really part of Kyoya's evil group, Disaster. When Gao mentions he has an "ultimate" Dungeon World deck, the school principal Ikarino overhears him and transports Gao and his classmates into an inescapable dungeon. In order for them to leave, Ikarino must be defeated in a Buddyfight. Gao manages to do so with his Dungeon World deck, and the entire class returns to the homeroom.