In Valhalla District 3, a place where all crimes are permitted,
the only way to live like a human being is to fight your way to the top of the Octagon—
killing others and climbing higher with every victory.

Pi, who has earned recognition for his exceptional combat skills and lives under the favor of executive Dexter, never questions the world he lives in—
until one day, he meets Oliver and discovers the existence of the civilian world beyond Valhalla.