Battle Royale takes place in an alternate timeline—Japan is a national socialist state, known as the Republic of Greater East Asia (大東亜共和国 Dai Tōa Kyōwakoku). Under the guise of a "study trip," a group of students from Shiroiwa Junior High School (城岩中学校 Shiroiwa Chūgakkō) in the fictional town of Shiroiwa (Kagawa Prefecture) are sleep-gassed on a bus. They awaken in the Okishima Island School on Okishima, an isolated, evacuated island southwest of Shodoshima, also in Kagawa Prefecture. They learn that they have been placed in an event called The Program. Officially a military research project, The Program is a means of terrorizing the population, of creating such paranoia as to make organized insurgency impossible. In the manga, the economy had collapsed and the government created The Program to revitalize the economy. According to the rules, every year since 1947, fifty 3rd year junior high school (14-15 years old) classes are isolated, and each class is required to fight to the death until one student remains. Their movements are tracked by metal collars, later identified as Model Guadalcanal No. 22, around their necks which contain tracking and listening devices; if any student should attempt to escape The Program, or enter declared "forbidden zones", a bomb will be detonated in the collar, killing the wearer. If no student dies in any 24 hour period, all collars will be detonated simultaneously.
After being briefed about The Program, the students are issued survival packs which include a map, compass, flashlight, food and water, and a random weapon or other item, which may be anything from a gun to a paper fan. During the briefing, two students (Fumiyo Fujiyoshi and Yoshitoki Kuninobu) anger the supervisor, Kinpatsu Sakamochi, who kills both. As the students are released onto the island, they each react differently to their predicament; beautiful delinquent Mitsuko Souma murders those who stand in her way using deceiving tactics, Hiroki Sugimura attempts to find his best friend and his secret love, and Shinji Mimura makes an attempt to escape the Program.
