In a world where everyone has eight skill slots, people can put skills like “Strengthen arm ★” and “Fire Magic★★” from skill orbs, abilities that prove extremely useful for survival. The total number of stars in the skills cannot exceed the number of slots. Reiji works as a slave mining skill orbs. Along with his precious older sister, Lark, they work gruelingly in the mines until a rebellion occurs at the mine, and Reiji gets his hands on a ten-star, a so-called “overlimit” skill, called “World Ruler.” From a powerless slave to having an ability that surpasses human limits, Reiji gains unfathomable power but is separated by Lark in the chaos of the revolt. (Source: MU, edited)