Aiyori Aoshi appears as one of the participants of the Nightmare Game in Chapter 2, Mental Prison.
He is tall with a slim figure. He usually has a wide knowing grin on his long face and wears glasses that compliment his thin eyes. He wears a suit; a light blue dress shirt, a dark blue tie and a black jacket.
He is given the armband with the number 1 and is the first to roll the dice and gets a 6, Spirit, and had none of his senses deprived. He appears later when Ishimakura Takuo takes the food that is meant for all the participants and uses verbal violence, revealing Ishimakura's past when he was bullied. Aoshi gets all the other participants excluding Fukurokouji Meguru, Kukuri Momoko, Amazono Daisuke and Makabe Yousuke to participate in his plan to verbally abuse Ishimakura, eventually leading to his death. Aiyori was momentarily shocked by his unpleasant death, but assured the other participants that he deserved it. Before the night is over, he and the other participants are told by Fukurokouji and Kukuri about Shirakogawa's attempt to kill both of them and thinks that he should be punished by verbal violence like Ishimakura. However, Niko Akira and Utsuromiya Fuyumi voice their uncertainity and Aoshi comes up with another idea; to ignore Shirakogawa altogether. The participants agree and the first night passes.