Yuri Yountz used to enjoy taking old relics from the forbidden crash site. When he gets caught by a mysterious black-armored being, that all changes. In his struggle, he escapes with a stolen key. After Yuri returns to his final year at Academy to learn the truth about Jupiter Arias and the Great Mutant War, he discovers that in addition to his usual juggling of friendships, he has a new set of problems all attributed to the key. Now Yuri must uncover the truth behind the Dragon Key while he travels through a land long-isolated by the Net.