15 years ago, a hyperspace gate emerged, connecting Earth to a mysterious world filled with mythical creatures. The arrival of over 2 million of these beings in San-Teresa sparked problems such as drug use, prostitution, and trafficking. To combat this, the San-Teresa Metropolitan Police department created a new unit. Kei Matoba, a former JSDF soldier known for his defiant spirit, is a high-ranking officer in the new department. However, after his colleague and friend, Rick Fury, dies during a mishandled fairy trafficking case, Kei is determined to seek revenge. In an attempt to aid him, the department pairs him with Tilarna Exedilika, a royal from the Farbani Kingdom and one of the respected Knights of Mirvor. Her goal is to save a noble fairy that Kei came across during his previous case. Despite his initial unwillingness to work with non-humans, Kei agrees to collaborate to solve the case, retrieve the missing fairy, and serve justice for his partner's death.