Btooom!

22-year-old Sakamoto Ryota, who is unemployed, resides with his mother and just plays video games during the day. Although he may not stand out in the real world, he is one of the best players in the world at the combat game Btooom. He wakes up one day without knowing how or why he got there, on what appears to be a tropical island. A mysterious being that Ryota encounters while exploring the island assaults him by tossing an odd-looking bomb at him. Then Ryota understands that he is both locked in a real-world simulation of his beloved game and that his life is in jeopardy. To discover why they were placed in the game in the first place, Ryota and the other "players" must now make it through the nightmare.