Арк

A Japanese gamer who, after falling asleep playing an online game, finds himself trapped in his game avatar, seemingly transported to a different world. In the game, the only paid avatar was a full-body skeleton, which he chose despite wearing full-body armor. When arriving in this world he still is in the body of a skeleton, which he figures out to be a curse. So he thinks up his own background story to be "a knight that is trying to find a cure for his curse".