Sakamoto Ryota still has no job at age 22, and leads a rather dull life. But in the online game, BTOOOM!, he's stronger and more highly respected than anyone else. However, the game he's playing now is no longer virtual, but real. He's been sent to a deserted island with only a BIM supply and no clue why he's being coerced into fighting and killing. The players are now stuck in a real life version of BTOOOM!, not even knowing the reason why.