Kiriyama Family in the manga.
Members
- Kazuo Kiriyama (Leader) (Novel and Manga only)
- Mitsuru Numai (Leader in Movie) (Second in command in Novel and Manga)
- Ryuhei Sasagawa
- Hiroshi Kuronaga
- Sho Tsukioka
- Izumi Kanai (film version only)
Pre-Program
A gang lead by Kazuo Kiriyama who is the leader due to his genius level IQ and his talent of quickly adapting to any situation. However he doesn't get involved in much of the gang's bullying and only gets involved if someone challenges him. The second in command of the gang is Mitsuru Numai who appointed Kazuo leader after Kazuo defeated another gang with ease while Mitsuru was beaten. He then becomes very devoted to him. The other members are also in awe of Kazuo and thus could be their reason for being involved in his gang.
Mitsuru's gang in the movie.
In the flim, due to Kazuo being a transfer student, The Kiriyama Family doesn't exist, but there is a gang headed by Mitsuru Numai. It could also be assumed that Izumi Kanai was a member of the Kiryiama gang in the film as it is suggested that she wasn't there by accident unlike the novel and manga.
During the Program
In the Novel and Manga, Kazuo gives a note to his gang telling them to meet him at the southern tip of the island when the students were released from the school. All except Sho Tsukioka arrive. Izumi Kanai also arrives but it only happens to be at the wrong place at the wrong time. Izumi is stabbed along with Hiroshi Kuronaga and Ryuhei Sasagawa. Mitsuru Numai arrives later and sees the dead bodies,when he asks why Kazuo simply replies that it was by chance that they died since he flipped a coin to decide to play the game or not. Kazuo then shot Mitsuru shortly after explaining. Sho Tsukioka witnesses this event and decides to only follow Kazuo unnoticed until the game is almost over. In which Sho planned to kill Kazuo,thinking by that time Kazuo would be weakened. Eventually Kazuo realizes that Sho is following him and tricks him by going to a restroom that's in a area that's about to become a danger zone. While in the restroom Kazuo cuts the bottled water to make it seem like he is taking a piss. Sho figures out Kazuo's plan at the last minute and his collar explodes. Kazuo himself is later taken out end game and is killed by the combined efforts of Shogo Kawada,Shuya Nanahara and Noriko Nakagawa.
In The film, Numai's gang takes Kazuo hostage and believe that he is a spy for Kitano. Kazuo manages to get an opening, grabs Ryuhei's uzi, and kills every member of the gang. Izumi is also a member in the film version, and is the last member to be killed by Kiriyama.