After being summoned to another world, Takumi awakens as the world's first "Hacker," possessing the extraordinary ability to manipulate the numerical values of skills and statuses. His adventures eventually bring together an unusual party: Mia, another person from Earth; Karla, a princess of the demon race; and Gail, Karla's bodyguard. After visiting the Dwarf Kingdom and learning more about the history and true nature of their world, Takumi and his companions set their sights on their next destination: Zoff, the royal capital of the demon territory.

A war is brewing between humanity and the demons, but the conflict isn't as straightforward as it appears. The elves have been manipulating events from behind the scenes, engineering a confrontation between the two races for their own purposes. Determined to prevent the coming war, Takumi and his companions head into demon territory to meet the Demon King himself. With a power capable of rewriting the very numbers governing this world's inhabitants, Takumi intends to hack his way through whatever stands between him and stopping the conflict.

Note: This is a reboot adaptation of the light novel of the same name. A previous manga adaptation was discontinued after two volumes.