
The story unfolds in the worldview of multiverse theory, where there is not just one universe. In the overlapping multiverses labelled as "Cosmo Layers", there exist other Earths that are identical to the Earth we live on. Gavan Infinity is a Space Sheriff who can transcend dimensions. What kind of cases will he solve in the diverse dimensions he is set in, and why can he transcend dimensions? A new Gavan legend never before seen begins!

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 Records Division, enduring daily ridicule from detectives in the Criminal Investigation Division.
Few know his true purpose: investigating transdimensional Emorgear crimes.
Reiji now heads for "Multiverse Earth 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 Unit...!