The story of Xeno Fighters R involves BRES, a group of humans subverted by the hostile Keto. BRES and the Keto extraterrestrials attack ATHENA through various periods in Earth's war history, using the wars as cover to their operations to destroy the Earth. The guest fighters do not have any connection to the story.

The story of Xeno Fighters R involves BRES, a group of humans subverted by the hostile Keto. BRES and the Keto extraterrestrials attack ATHENA through various periods in Earth's war history, using the wars as cover to their operations to destroy the Earth. The guest fighters do not have any connection to the story.