"ACCA: 13-Territory Inspection Dept. Regards" is set in the fictional kingdom of Dowa, a nation divided into 13 distinct districts, each with its own unique culture and governance. The kingdom is held together by ACCA, a powerful administrative organization responsible for overseeing the welfare and stability of the territories. The story centers on Jean Otus, a high-ranking officer in ACCA's Inspection Department, known for his calm demeanor, sharp observational skills, and love of cigarettes and pastries. Jean is tasked with conducting routine audits across the districts, ensuring compliance with ACCA's regulations and uncovering any signs of corruption or unrest.

As Jean travels through the districts, subtle hints of political tension and conspiracy begin to surface. Rumors of a potential coup d'état circulate, with whispers of a plot to overthrow the royal family and dismantle ACCA. Jean's seemingly mundane inspections take on greater significance as he becomes entangled in a web of intrigue, with various factions vying for power. His connections to key figures, including his childhood friend and ACCA's second-in-command, Nino, and his sister Lotta, add layers of complexity to his role in the unfolding events.

The narrative explores themes of loyalty, governance, and the delicate balance of power within a fragmented society. Jean's position as an inspector places him at the intersection of politics and bureaucracy, forcing him to navigate conflicting loyalties and uncover the truth behind the kingdom's growing instability. The story builds toward a climactic revelation about Jean's true identity and his pivotal role in the kingdom's future, tying together the political machinations and personal relationships that drive the plot.

The series is characterized by its methodical pacing, intricate world-building, and a focus on political intrigue rather than action. The 13 districts are richly detailed, each contributing to the overarching narrative and reflecting the diversity of the kingdom. The characters, particularly Jean, are portrayed with depth, their motivations and relationships adding nuance to the story. "ACCA: 13-Territory Inspection Dept. Regards" offers a compelling exploration of governance and identity within a meticulously crafted fictional world.