Kouki Yoshimune

A story of the bonds between those who fight, in a world pushed to its limits. On one of the countless parallel worlds that exist throughout spacetime, humanity has fought a decades long war against the BETA, hostile extraterrestrial invaders, using humanoid fighting machines called Tactical Surface Fighters. This is a story of how humanity lives and dies while on the brink of extinction...

Germany was divided into East and West after WWII, where citizens of either treated the other side as enemies. In the midst of Cold War, however, the Earth was invaded by an alien life form landed on Kashgar, Xinjiang Uyghur Autonomous Region, known as "Beta." Now, ten years after the first contact, East Germany, formally German Democratic Republic, has become the front line.

In the year 1973, alien species known as BETA (Beings of Extra Terrestrial origin which is Adversary of human race) came to invade earth. During the next 30 years, they have conquered most of the Eurasian continent, effectively decreasing the world population by billions. In response to their unique behavior, a new type of mobile mechanical humanoid weapon was developed, known as Tactical Surface Fighter (TSF). In the year 2001, elite pilots from around the world start to gather at a UN base in Alaska named Yukon to participate in the Prominence Project. This project is a joint effort between Russia and America on research and development of next generation of TSF. The job of the pilots is to test the prototypes, which occasionally involves pitting them one against another...

The original 2003–2010 series by âge, released across multiple distinct VN's. In a world ravaged by alien BETA invaders, high-school student Takeru Shirogane is thrust from peaceful Japan into brutal mecha warfare and devastating personal loss.