RealPG

RealPG is a manga series by Yuuki Doumoto. It was serialized in Gangan Online.

Plot
Motoba Hitachi has lived a boring high school life, until his kouhai invited him to a real-life simulation event of Incubate Castle, an online game they both played. But, what seemed like a harmless replication of the game turned out to be as real as it could get. Now, Hitachi must find allies to get out and survive this reality of a game.