Kazuo Kiriyama

Kazuo Kiriyama was a ninth grader in a totalitarian Japan where the government instituted a law known as the BR or Battle Royale Act, which states that a randomly selected class of ninth grade students would be sent a remote island, armed with random weapons (anything from an Uzi to a paper fan), and made to kill each other until only one survives. The students are given bomb-collars which will detonate if the attempt to escape, remove the bomb, enter a forbidden "danger zone" The reasoning for this varies between the novel, manga, and film version of the story. In the novel and manga, the act of an alternate totalitarian Japan known as the Republic of East Asia (implying the WWII either ended in Axis victory or never happened). In the film, the BR Act is a government retaliation against youth opposition during a period of high unemployment and social unrest.

In Either case, Kiriyama's backstory is similar. Kiriyama is a sociopath who suffered from brain damage as a child that made him unable to sympathise or empathize with anyone, and gave him a violent demeanor. Kiriyama volunteers to take part in the Battle Royale for his own amusement. Kiriyama is initially armed with a paper fan, but manages trick another student in to thinking he is going the ally with him, then disarms him with his bare hands and uses the contestants Uzi to kill him and several others. Kiriyama takes their weapons, arming himself with a a handgun (the model varies between the manga, novel, and film, a wakizashi, two Mk II Fragmentation Grenades. Kiriyama then goes on to kill several others, including two girls who draw attention to themselves attempt to contact the main character and ally themselves with him, a girl named Mitsuko Souma, who is every bit as sociopathic as he is, and a boy who he kills in a particularly gruesome manner, decapitating him with his wakizashi and then placing a grenade in his severed head and throwing it at Shuya Nanahara, Noriko Nakagawa, and Shogo Kawada, the three protagonists of the series. Nanahara and the others escape. Nanahara, Nakagawa, and Kawada confront Kiriyama a final time at the scene his latest murders, a building consumed in flames by the untimely explosion of a car bomb, which Kiriyama's victims intended to use to destroy the building on the island used as a forward base by the government forces in charge of the Battle Royale event. Kiriyama is is finally killed by Shoga Kawada, who shoots him with a SPAS-12 assault shotgun.