Many millennia have passed since the demise of the superior civilization. Now, brave adventures are using mystical body-machinery excavated from the ruins of this ancient race. After Mag Launcher's parents disappear on an adventure, a lone girl appears at their house with a letter from Mag's father. ""You must protect this girl, Linear, until I return,"" is all that is written. When the army of the 8th Empire appears, Mag and Linear's true adventure begins.