The year is 1973 when the BETA, a race of aliens discovered on the moon, first arrive on Earth and begin their systematic extermination of the human race. Mankind's only hope lies with Tactical Surface Fighters, or TSFs, piloted by both military elite and would-be trainees such as Yui Takamura, a young girl descended from a long line of Imperial Guards. Alongside other amateurs, she finds herself on the front lines of a final defense against the bloodthirsty monsters, unaware of the brutal consequence that awaits them. Three years later, Yuuya Bridges, a half-Japanese, half-American pilot, is assigned to an elite United Nations squadron tasked with developing new TSFs to beat back the alien forces. As humanity struggles to survive, Yuuya must come to terms with his biases in dealing with both his teammates' and other culture’s tactical fighters, including the veteran pilot Yui Takamura herself.