Fifteen years ago, a hyperspace gate emerged in the middle of the Pacific Ocean, linking Earth to a strange world inhabited by fairies and monsters. The city of San-Teresa became home to over two million of these visitors from another world. Unfortunately, this population surge also brought its share of problems, including drugs, prostitution, and trafficking. To combat the rampant crime lurking in the city's shadows, a new department was established within the San-Teresa Metropolitan Police. Kei Matoba, a former JSDF soldier, is one of the department's top officers, despite his tendency to occasionally bend the rules. After a fairy trafficking case goes wrong, Kei loses Rick Fury, his friend and partner of four years, setting him on a path of vengeance. To assist with the case, the department pairs him with Tilarna Exedilika, a noble from the Farbani Kingdom. As one of the Knights of Mirvor, her duty is to rescue the noble fairy Kei encountered during his previous case. Despite his distaste for non-humans, he accepts the arrangement at his superiors' request. Now, this unlikely duo must set aside their differences to return the missing fairy to her homeland and avenge the death of Kei's partner.