Reiji Doki, an investigator for the Galaxy Federal Police, is Gavan Infinity—the sole individual in the cosmos authorized to bear the title "Space Sheriff Gavan." Yet he languishes in the marginal Archives Division, enduring daily ridicule from detectives in the First Investigative Division. Few know his true purpose: investigating trans-dimensional Emorgear crimes. Reiji now heads for "MultiEarth Λ8018," where an Emorgy Negative Wave threatens to expand across dimensions and potentially collapse the entire universe. Amidst Λ8018's chaos, he encounters Setsuna Aikokuin, captain of the Galaxy Federal Police's Special Forces, but...!