26-year old Marine, Nishikawa Amano, finds himself in another world after getting killed in a hostage rescue mission in Iraq. The world not only is fantasy-like, but also has RPG features, such as a leveling up system, and even the possibility of acquiring skills. But, he possess a unique attribute that no one does---the RULE attribute. it allows him to change the rules of the world, at the cost of all his gained levels. Will he become a man to bring about changes for the good, or a harbinger of death?