The Next Successor Of The Grimoire

2 years ago a person named "Fujimura Kazumi" found a door on his company that led to another dimension. After multiple types of researches on the other dimension, he decided that the top 5 players of the game he was about to release, would go there in 2 years. Murakami Sora got an invitation from his friend Nagai Tadashi, to participate in the event. Sora and four other people passed the door and started their adventure. After some time, the others found out Sora wasn't the one that was supposed to come in the other world and since they can't go back to earth, they try to eliminate him.