Ten years have passed since the discovery of inter-cosmic travel. The existence of three parallel worlds have been confirmed. What happens in one cosmos, even the slightest incident, can create a "butterfly effect� that influences events in the other worlds. In response to these discoveries, the "Dimension Police� and "Space Guardian Academy� are formed. The beautiful female investigator Ai is the Space Guardian Academy's top agent. Along with her trusted android partner, Bridge, she has been assigned to eliminate the inter-cosmic terrorist group DOUBT. Amidst the struggle, Ai finds herself challenged like she never has been before when allies become enemies, enemies become allies, and the mastermind behind the evil plot is revealed.