In the era of True Calendar (T.C.) 71, where most of humanity resides in space within the innovative Dyson Sphere, a city above Earth, two dominant powers emerge: the militaristic Dorssia Military Pact Federation and the economically influential Atlantic Rim United States (ARUS). Amidst this geopolitical tension, the neutral nation of JIOR thrives on economic stability. Haruto Tokishima, a typical high school student from Module 77 within JIOR's territory, experiences a seismic shift when the Dorssian military launches a sudden assault. However, the world's fate takes a dramatic turn as Haruto encounters the enigmatic humanoid weapon, Valvrave.