Bloody Junkie(2011)

Bloody Junkie

When Shouta finally finds a clue to his missing brother’s disappearance, he mysteriously wakes up in a room he’s never seen before.
The events of this room are broadcast online, and the only link with the outside is voice chat with the viewers of the broadcast.
In the midst of this extreme environment, a battle royale style murder game begins!

(Source: Yukihito)