As the attacks by the Mechanical Beasts continue to escalate, and Earth's defenders struggle to develop new technology capable of stopping them, the mystery surrounding our planet's greatest protector only deepens. After all, if a weapon is only as dangerous as the being who wields it, why has the robot-like goliath known as Reideen chosen a high school student like Junki Saiga to be its pilot? What is Reideen's real purpose here on Earth? Is it our last line of defense in this war, or could it actually be the cause of it? And how many weapons and capabilities does it possess that have yet to be seen? Solving these riddles could be the key to saving everything, but the clock is running down for the Vigilant Corps. The enemy is no longer content to simply attack from space-they're here, infiltrating our cities, and they already know who the pilot of Reideen is. As Junki and Hoshikawa find themselves the targets of both human and alien covert action, the battle for the fate of our world expands to an even wider front in REIDEEN - COLLECTION TWO!