Shuya Nanahara, a Japanese middle school student, attempts to cope with life after his father's suicide by hanging. Meanwhile, schoolmate Noriko Nakagawa is the only student attending class—3-B. Their teacher, Kitano, quietly leaves upon her tardy, apologetic arrival, but is attacked by student Yoshitoki Kuninobu and resigns after recovering from his wound.
One year later, class 3-B takes a field trip after completing their compulsory studies; however, the class is gassed and sent to a "briefing room" on a remote island, wearing electronic collars. Kitano explains that the class has been chosen to participate in this year's Battle Royale as a result of the BR Act, which was passed after 800,000 students walked out of school. The orientation video cheerfully instructs the class to kill each other for three days until only one student remains. Students resistant to their rules or entering one of the randomly placed "danger zones" for each day are to be killed by the collar's detonation. One of the 42 students, Fumiyo Fujiyoshi, interrupts the video by whispering to her friends; Kitano kills her on the spot with a thrown knife. While a shocked class is subdued by soldiers, Kuninobu openly confronts the viciousness of Kitano and the teacher slashes him with a knife (in the back of leg - the same area Kuninobu attacked Kitano two years earlier) before detonating his collar while Shuya, his best friend, watches in horror. Each student is provided a bag of food and water, map of the island, compass, and one item containing either a lethal weapon (firearm, sickle, knife, potassium cyanide) or an item apparently worthless toward survival (paper fan, binoculars, coat hanger, saucepan lid). The weapons are supposed to eliminate any natural advantage any one student might have over the others.
The program's first six hours see twelve deaths, four of which are suicides. Brazen, mute "exchange student" Kazuo Kiriyama and quietly deranged classmate Mitsuko Souma soon become the most dangerous players in the game, while another exchange student, Shogo Kawada seems somewhat more merciful. Shuya promises to keep Noriko safe for Kuninobu because he was in love with her, but never told her. Other students have various goals in the game: Shinji Mimura and his friends plot to hack into the military's computer systems and destroy their base of operations;Hiroki Sugimura searches for his best friend Takako Chigusa and his love interest Kayoko Kotohiki. Chigusa runs into Kazushi Niida, who is sexually obsessed with her; Chigusa kills him after he attempts forcing himself on her, but is herself killed by Mitsuko. Kawada teams with Shuya and Noriko, and reveals that he won a previous Battle Royale at the cost of his girlfriend, Keiko; he now swears vengeance. The trio are forced to separate when Kiriyama attacks, and Sugimura rescues Shuya, assisted by his assigned "weapon," a GPS tracking device.
Shuya awakens bandaged by Yukie Utsumi in the island's lighthouse, where she helps reorient him to the events of the past 14 hours; five other girls on the school's cheerleading squad have also been guarding and hiding out in the building, apparently since the beginning of the program. Utsumi gathers the girls around the dining table to weigh in on a possible method of escape from the island which Shuya has informed her of. Yuko Sakaki, thinking that Shuya murdered a friend of hers, attempts to poison Shuya's food, but it is inadvertently eaten by one of the girls, killing her and sparking a massive, fear-fueled gunfight resulting in all the girls' deaths—except Yuko. She realises the enormity of her paranoia and commits suicide, jumping from the deck of the lighthouse.
Shuya returns to Noriko and Kawada, and they set out to find Mimura's group. To a small warehouse, Sugimura tracks down Kotohiki, who panics and kills him shortly after; Sugimura professes his love before dying. Kotohiki cries in despair, and is found and killed by Mitsuko. Watching from the rafters, Kiriyama then guns down and kills Mitsuko after she sadly dispenses some fitting advice to her two (dead) classmates.
Upon the rapidly-consecutive deaths of Sugimura, Kotohiki and Souma, all of the seven students remaining are either preparing or willing to completely subvert the operations of the "game" – save for the psychopathic Kiriyama. "The Third Man", a hacker group consisting of Mimura, Iijima and Yutaka, successfully infiltrate the military's computer system and prepare to destroy the perimeter using a truck converted into a fire-bomb. However, at the last second they are found by Kiriyama, who kills them all, but Mimura manages to detonate the truck, seriously injuring the killer. When Kawada, Noriko and Shuya arrive at the hackers' burning base, Kawada confronts and kills the shrapnel-blinded, Uzi-armed Kiriyama with his SPAS-12 shotgun.
On the morning of the final day, Kawada, aware of the collars' internal microphones, takes Shuya and Noriko aside and fakes their deaths. Suspecting that Kawada has won through manipulation of the BR system, Kitano ends the game and dismisses the troops before establishing final protocol, intent on personally killing the young man. Kitano realizes that Kawada, and not Mimura, has hacked into the game's intranet system months beforehand, and has now disabled Shuya and Noriko's tracking devices. Kitano unveils a homemade painting of the dead students, with Noriko indicated as the winner. He reveals that he was unable to bear the mutual hatred between him and his students, having been rejected by his daughter, Shiori. He also confesses that he always thought of Noriko as a daughter. He asks the confused, reluctant Noriko to kill him, but is quickly shot by Shuya after he threatens her at gunpoint. As he falls, Kitano shoots, and it is shown that the weapon in his hand was a mere water-gun. Suddenly, his phone rings, and Kitano sits down to answer it, telling Shiori that "if you hate someone, you take the consequences" before finally dying. Shuya, Noriko and Kawada leave the island on a boat, but Kawada dies from injuries sustained in his gunfight with Kiriyama -- "glad" that in the end, he "found true friends."
Shuya and Noriko are declared fugitive murderers, and last seen on the run in the direction of Tokyo's Shibuya train station, they face an uncertain future but Shuya is assumed to love and protect Noriko for the time.
I may be late in posting this since I know some of you are already finished this movie.
I find this movie very interesting it's not very gore like everyone talked about, I have watched much gore movies than that but the difference between this movie and other gore movies are the realism of the details in terms of fighting and the blood, i just noticed that other gore movies have blood that much look like a water with color I may based it on the movies i watch so far so just calm guys.
The plot was great I remembered the movie HUNGER GAMES, seem like Hunger Games was based on Battle Royale they almost got the same plot and the twist of the story. How About you guys? you feel the same way??
The movies was an 18-R because there are many fights scenes not suitable for minors.