"Special 7: Special Crime Investigation Unit" is set in a world where humans coexist with dragons, elves, dwarves, and other mythical beings. The story unfolds in Tokyo, where a specialized police unit, the Special 7, operates to combat supernatural crimes. The unit is composed of individuals with unique abilities and backgrounds, each contributing their expertise to solve complex cases involving magical and mythical elements.

The protagonist, Seiji Nanatsuki, is a rookie detective with a strong sense of justice and a mysterious past. He joins the Special 7 after a chance encounter with the unit during a high-stakes investigation. Seiji's innate ability to sense danger and his unwavering determination make him a valuable asset to the team. The other members include Ichinose, a skilled swordsman with a calm demeanor; Shiori Ichinose, a sharp-witted analyst with a knack for technology; Akane Shikisai, a powerful mage with a tragic history; Boss, the unit's leader with a commanding presence and strategic mind; and Rokusuke Endo, a laid-back but highly skilled marksman.

The narrative revolves around the Special 7's efforts to thwart the plans of the Nine, a notorious criminal organization seeking to disrupt the fragile peace between humans and mythical beings. The Nine's leader, a enigmatic figure known as the Dragon King, possesses immense power and a deep-seated grudge against humanity. As the Special 7 delves deeper into their investigations, they uncover a web of conspiracies, betrayals, and ancient conflicts that threaten to plunge the world into chaos.

Throughout the series, the Special 7 faces numerous challenges, including internal conflicts, moral dilemmas, and the ever-present threat of the Nine. The team's camaraderie and individual growth are central to the story, as they learn to trust one another and harness their unique abilities to overcome seemingly insurmountable odds. The series balances action-packed sequences with moments of introspection, exploring themes of justice, identity, and the coexistence of different species.

As the Special 7 closes in on the Nine, the stakes escalate, culminating in a climactic confrontation that tests the limits of their resolve and unity. The series concludes with a resolution that ties together the various narrative threads, leaving room for potential future developments while providing a satisfying conclusion to the immediate story arc.