Humans have successfully spread into space and begun to live in autonomous galactic colonies in the 71st year of the True Era. The planet is divided into two great nations: the Atlantic Rim United States (ARUS) and the Dorssia Military Pact Federation (Dorssia)—superpowers that fight each other on Earth and in outer space. In this war-torn period, Japan and the Islands of the Oceanian Republic (JIOR) live peacefully and economically, remaining impartial between themselves and their militant neighbors. Kakumeiki Valvrave begins in a JIOR colony in outer space, when 17-year-old Haruto Tokishima's calm life is thrown upside down when an unexpected Dorssian armada penetrates the neutral colony. Their goal is to seize the Valvraves: a powerful but rumored family.