Fukurokouhi Meguru is first introduced as a drunk person at a club, crying as he asks the bartender to give him another drink. When he grabs the bartender by his shirt and the bartender calls out for security, a drink is slid towards Meguru's direction by a complete stranger. After Meguru thanks him, the stranger claims that he needed someone to talk to and Meguru begins to explains his situation starting by his younger sister who has heart disease and requires a heart transplant to live but no matter what he did, he failed in raising the money. He worked to get that money but could not earn enough and a support group approached him and helped him raise money to get a 100,000,000 yen. However, the support group was actually a con and they took the money that he had raised and ran. The stranger suggests gambling, but not of money but of his own life, in the "Nightmare Game". When Meguru was told of the "Nightmare Game", he was not interested in it but was left with the stranger's card as contact. The next day his sister collapsed though and as a result, he contacted the stranger and agreed to participate in the "Nightmare Game". The day before his sister's birthday, he was contacted and told that he would be leaving for the games only a few minutes before the departure time. He was taken away in front of his sister and was told as he was being driven to the site that he was tricked and that his sister's doctor was paid to give her sleeping pills to fake a collapse. Soon after, he was blindfolded and taken to an unknown destination where he met nine other participants.
Meguru looks like a typical lean boy, appearing to be of average height with pale skin. Meguru has untamed light brown hair held by a white headband and has brownish eyes. He wears a simple singlet with an orange shirt over it.
He is assigned the number 9 as a result of the of the random distribution of the wristbands. He first rolled a 6 with the Six Sense dice which means Spirit, and therefore had no senses deprived.
The first participant that he talks to is Kukuri Momoko, as he wants to help her since she rolled a 1 and was deprived of sight. He realises that they are both alike in that she does not like gambling. Meguru helps guide Kukuri to her room and is humourously embarrassed by holding Kukuri's hand as it is his first time holding a girl's hand. However, after leading her to her room, an announcement was made that the food had been delivered and as they go to collect it, Ishimakura Takuo holds all the food and claims it as his. Takuo says that they will have to pay him to get the food, but gets intercepted by Aiyori Aoshi and uses verbal abuse to get Takuo to reach his emotional instability limit and die. The rest of them join in except Meguru and Kukuri. Meguru asks them to stop, not wanting Takuo to die but ultimately is accused of helping Takuo. When Takuo reaches the limit, he asks Meguru to help him in vain before dying. As a result from the shock of his death, Utsuromiya Fuyumi asks to work with Meguru and Kukuri. Before everyone goes to sleep, Kukuri asks Meguru to stay because she does not want to be alone and they discuss what has happened. Meguru comes to the conclusion that the Mental Prison is based on the Stanford Prison Experiment.
Unexpectedly, Shirakogawa Romero calls them, apologising about what happens to Takuo and asking if he can come into their room, bringing a boombox for Kukuri that he borrowed from the Music Room. However, his real intentions was for both of them to reach their death by being trapped and listening to a 24 hour medley of heavy metal that appears to stress Kukuri greatly. Romero lets his true personality come through, saying that he is actually not interested in the money that can be made by playing the game, but in the pleasure of killing people, calling himself a "naughty sadist" and "human destroyer". Meguru and Kukuri retreat to the bathroom in hope to deafen the sound of the music and Romero takes this opportunity to destroy their supply of food. Meguru makes a plan and succeeds, managing to get Kukuri out to call for help. However, Romero does not give up, turning off the lights so that he is not seen and stabbing Meguru. Meguru is found by Kukuri and Utsuromiya but Romero was not eliminated as there was not sufficient evidence that he committed violence according to Black Tapia. Meguru gathers the other participants and tells them what happened. They also begin to talk about the their situation and the reason why they are a participant, apart from Amazono Daisuke and Utsuromiya who pass and Makabe Yousuke, who no one understood. Aiyori then says that Shirakogawa should be punished, and the group unaminously voted that everyone would ignore Shirakogawa before going to sleep. However, Meguru and Kukuri sleep in the same bed as a result of Kukuri's insecurity.