High school martial artist Ryoma Mikoshiba is summoned to another world by the O'ltormea Empire, which enslaves the people it calls forth and discards the weak. After he learns how the empire exploits its summons, Ryoma cuts down a high-ranking O'ltormean official and flees into the wilderness. Saving the twin sisters Sara and Laura wins him his first loyal followers, and with them he sets out to carve a place for himself in this hostile new world. This is the manga adaptation of Ryouta Hori's light novel.