Btooom!

Ryouta Sakamoto is an unemployed man living with his mother, his only claim to fame being Japan’s best player of the online game "Btooom!" His quiet life takes a drastic turn when he wakes up stranded on a remote island, a small green crystal lodged in his left hand and no recollection of how he arrived there. To his horror, someone has recreated the game in real life-but this time, the stakes are survival. Each player is given a bag of specialized bombs called "BIM" and must kill seven others to collect their crystals and escape. Though Ryouta refuses to resort to violence at first, he soon learns that many of the other participants are far from friendly. Forced to fight for his life, he allies with Himiko, another "Btooom!" player, as they struggle to survive and uncover the truth behind the deadly game.