The story starts off with showing what players are and showing how Kouga and Jin were friends when they were young than the story makes a leap forward in time and follows the 2 main characters - Jin Kanzaki, a young man with the ability to transform into a superhuman being known as ZET, and Kouga Amagi, a young man with a strong sense of justice who uses technology to fight as ALPHAS. The fates of these two men and those around them intertwine as they fight to protect mankind and destroy monstrous abominations known as Players, who ironically are the creations of the Amagi Corporation, the company founded by Kouga's grandfather, Mitsugai Amagi.