Hai to Gensou no Grimgar

When Haruhito wakes up, he is in darkness. He no longer knows where he is, who he is, or where he comes from. Around him, men and women he doesn't know are in the same situation. They then discover that they are in a world similar to a video game, called "Grimgar". To survive in this hostile environment and understand what is happening to them, they will have to team up, cooperate, and learn new skills.