A young man awakens to find himself in what he is told is the depths of a dungeon. He is told he will have a month to train before setting out on his own to make his own dungeon. Most dungeons cores are born with all the knowledge they are required to survive, but for some reason this young man has trouble adjusting.  The story follows the life of dungeon core #212 while he discovers just what it means to be a dungeon core.