The ordinary boy Kazuki is summoned to another world as a "hero," but he has his right hand cut off by humans and is banished with the stigma of being "useless." Just as he is on the brink of death, a girl named Ruta, claiming to be a survivor of the supposedly extinct ancient dragon race, appears before him. "Do you wish to live? However, you will have to work until you die as my servant." Kazuki forms an alliance with Ruta for revenge and gradually awakens to the hidden powers of "Soul Power (Chakra)" and "Soul Armor (Karma)"...! Together with dragons, elves, demi-humans, and others oppressed by humans, let's turn the world upside down!