Female Room 8 The host of the game, Citizen. A female character with long hair wearing a pink beanie; she seems to have been quiet during her third year of middle school. However, after inheriting her parents' company and becoming wealthy, she immediately drives a supercar to hold a reunion at the Deongdeuk Park campsite and suggests playing a Mafia game once night falls. Based on most of her dialogue after Episode 2, she appears to be quite emotionally fragile. She killed Koru in Episode 2.

Female Survivor Bacon's mother. In the basement room in Episode 2, she hears from Bay, who came to deliver news about Bacon, that Bacon is a troublemaker whom no one would kidnap and isn't the type to get kidnapped, so she doesn't believe it at first. However, upon seeing Bay get into a police car, she follows along. In Episode 3, 'Room of Faith, Night of Betrayal,' she flees with Bay after witnessing Police Subordinate 1 being shot and killed by a masked figure. In Episode 5, 'Cracks Engraved by Gunfire,' she flees with Bay, subdues an armed member of the hosting side without any equipment, and obtains a gun. She then shoots and kills a masked person passing by the bodies of the self-destructed police, and while running from five armed thugs, she tells Bay to escape first. She kills three of the thugs, excluding the two who went to catch Bay. Right after saying she needs to go find Bay, she is struck by Crow Mask with a bat and knocked unconscious.

Female Room 3 Mafia A female character with gray hair. she is hostile toward her father, who abused her when she was young. When her family's situation became precarious because of her father, she intended to take a taxi to the reunion, but her father, claiming it was a waste of money, insisted on driving her himself. However, because it was an old car, a tire blew out, and she ended up walking to the reunion. Perhaps due to her family circumstances, she has a cold personality. Mentioning Luke in Episode 1 suggests something happened between them. Revealed to be a Mafia member in Episode 3, 'Room of Faith, Night of Betrayal,' she is effectively the female protagonist of this work. She killed Karu in Episode 3 and Lien in Episode 4. In Episode 6, 'In the Name of Older Brother,' she seems to realize Luke is a doctor, and she murders Luke in Episode 8.

Male Room 1 Police The undisputed protagonist of the work. While spending a boring weekend, he receives a call from Rachan, a former classmate from his third year of middle school. The call is an invitation to a reunion for their former classmates, and Bacon immediately steals Ammicon's car(...) to go to the reunion. His role in the Mafia game is Police. On the night of the second day, he investigated Karu but found him to be a Citizen. In Episode 6, after comforting Rachan, he suspects Ruyo of being a Mafia member.

Male Appears to hold a high rank. Serial number 1 on the Executioner List. His code name is RCF. He is in charge of speaker recordings. He captures Ammicon and binds her arms with iron bars. At the end, he shoots and kills Sera's father. Crow Mask is actually Rachan's father. This is revealed at the end when he kills Sera's father and says, "Rachan, this is your father's final revenge."

Grunt Mask Appears to have the lowest status among the hosting side. They basically carry guns and try to shoot and kill any intruders on sight.

Bat Mask When Bacon's friends gather and try to start the Mafia game, he suddenly intrudes, knocks out everyone present except Bay with a bat, and drags them to the game location in a truck.

Sera's father. After his wife Erin fell into a vegetative state and died, he followed a friend's advice and squandered Erin's life insurance money, putting the family's finances in jeopardy. In Episode 1, he drives Sera to the reunion in an old car, but a tire blows out, leading Sera to curse at him. According to facts revealed in Episode 7, he was a domestic abuser whose condition was serious enough that the police had already visited once. His domestic violence provided the catalyst for Sera becoming violent later on. Because of this, the violent Sera abused Rachan, which contributed to the Mafia game being held; thus, he is effectively the root of all evil in this work. However, seeing how he visited the funeral in Episode 10 and was overcome with grief while looking at Sera's portrait, it seems he suffered a mental breakdown after Erin fell into a vegetative state and acted violently toward Sera. He eventually dies in front of his daughter's portrait after being shot by RCF.