Hai to Gensou no Grimgal summary:
Before Haruhiro had realized what happened, he was surrounded by darkness. Why was he here? Where was here? Even now, he still didn’t know. Those around him were the same as him, no one remembered anything other than their own names. And when they emerged from the darkness, the world that awaited them seemed like something out of a videogame. In order to survive, Haruhiro forms a party with the others, learns fighting skills, and as a soldier in the reserve force, takes his first steps into the world of Grimgal. What awaits him there, he doesn’t know… This the story of an adventure born from the ashes. Based on a light novel: https://www.mangaupdates.com/series.html?id=116485