Battle Royale is the 2000 Japanese feature film adaptation of the controversial 1999 Japanese novel of the same name by Koushun Takami, who later published a 3,000 page illustrated manga version of the story. The premise of the film revolves around "The Program", a government-sponsored event which forces randomly selected junior high school students who are armed with various weapons to eliminate each other until there is one remaining survivor. The film would spawn a 2003 sequel: Battle Royale II: Requiem.
Boy #20 (Kyouichi Motobuchi)'s weapon is a Smith & Wesson Model 19 Snub Nose revolver with rubber grips. After his death the gun is used by Boy #5 (Shougo Kawada) and later given to Boy #15 (Shuya Nanahara).
Boy #17 (Mitsuru Numai)'s weapon is a Walther PPK .380ACP. This later becomes Kazuo’s backup weapon which he keeps tucked in his belt, but the audience never sees it .
In all three versions, Boy #19 (Mimura)’s weapon is a Beretta that appears to be either a nickel plated 92FS or an Inox. It's got a polished shine to it in either case.
Girl #12 (Haruka Tanizawa) is assigned a Browning Hi-Power pistol. In a continuity error, Girl #10 (Hirono Shimizu)'s M1911 switches to a Browning Hi-Power during her initial appearance.
Boy #5 (Shogo Kawada)'s assigned weapon is a stockless Franchi SPAS-12 shotgun. As with most on-film portrayals of the SPAS-12, the semi-automatic setting is ignored in favor of the manual pump-action setting.
Girl #16 (Yuka Nakagawa)'s weapon is an IMI Micro-Uzi fitted with some sort of flash suppressor. After she dies, the gun is used by Boy #15 (Shuya Nanahara).
Some of the soldiers seen during 3-B's introduction to the BR Program are seen with M16A1s (denoted by their full-auto capability displayed in the scene) outfitted with M16A2 handguards.