A manga by Natsume Ono, which ran from 2013 to 2016 in Monthly Big Gangan. It was adapted into a Winter 2017 anime produced by Madhouse.
In the Kingdom of Dowa, there exists an organization called Acca, which provides services to each of the 13 distinct districts of the kingdom. Acca is independent from the crown, and from each district's leadership, yet there is always a power struggle between these sides - and other interests that want to affect the kingdom. Jean Otus is the deputy chief of Acca Headquarters' Inspection Department. His job is to go to all of the Acca branches in all of the districts and audit them, to weed out corruption.
It is the 100th year since the struggles that led to the creation of Acca. The king is getting old, the heir apparent seems incompetent, and there are rumors swirling everywhere about a possible coup d'etat - and Jean finds himself at the center of those rumors. What is really going on? Who is planning what? And what will happen in the future of Acca?
ACCA: 13-Trope Inspection Dept.
- Big Applesauce: Badon District is quite clearly based on New York City.
- The Coup: The major plot of the series is Jean investigating rumours of a coup d'etat, with additional rumours claiming he's the go-between carrying details between the districts. It exists. Prince Schwan is a Royal Brat who most people thinks is incompetent to be the next king and plans to eliminate ACCA. Against this, ACCA and the district chiefs plan to remove Schwan and install Jean as the next king who will maintain the current system. It's actually a cover for the Lilium family and Furawau to take over the whole kingdom. In the end, Mauve and Jean manage to defuse this plot and inspire Schwan with a little more respect for ACCA.
- Culture Chop Suey: The districts certainly are unique, though how so many different styles ended up so close together is its own issue.
- Dirty Cop: Rail turns out to be a fledgling one. He's so resentful at people he assumes have it easier than him, he thinks that's a good excuse for fencing confiscated goods. He's been caught a lot of times for a rookie.
- Double Agent: Nino is watching Jean for Grossular, but he's taking calls for someone else...
- Easily Forgiven: All things considered, Jean and Lotta forgive the royal family for attempting to have them both assassinated. Especially jarring since Nino is nearly killed defending Jean from an assassin's bullet.
- Faking the Dead: The second princess didn't die in the shipwreck. The train crash, however...
- Fantasy World Map: Shaped like a bird with a leaf in its beak. (The leaf is Badon)
- Food Porn: Famous for it. It's almost as vital to this series as the plot. Mostly bread and cakes.
- Hero Worship: Jean has a great deal of admiration and respect for Chief Grossular because he consoled him after the death of his parents due to the train crash. He later assumes that Grossular was more than aware that Jean had royal blood at the time, lending more significance to the kindness he dispensed towards Jean, especially considering the fact that his mother was a royal princess.
- Hidden Backup Prince: The two children of the supposedly-dead second princess. Jean is older than Prince Schwan, making him the real heir to the throne.
- Internal Affairs: The titular Inspection Department. They audit the Acca branches in the districts for corruption.
- Lady Land: Korore is a mild example. There are men, but most positions of influence are filled by women, and the district itself has a Victorian aesthetic.
- Lighter and Softer: A lot of people expected it to be like Joker Game or 91 Days. It's more like 91 Cakes. Posters like this◊ don't help, though.
- The Man Behind the Man: Grossular is poised as an antagonist with dubious motives from early in the series, though it's later revealed that his strings are being pulled by Lilium and he has considerably less power on his own than what's shown in the beginning. Still, it's through his efforts that ACCA has maintained some semblance of order in spite of ideological and territorial differences.
- No Full Name Given: Most of the characters, other than Jean and Lotta Otus. Lilium and his brothers are all just called "Lilium", it seems.
- Older than They Look: The revelation that Nino was 25 when he enrolled in the same high school as Jean, which Jean himself mentions was 15 years ago means that in present time he's around 40. He looks like he's in his 20s. To a lesser extent, Jean also looks very young for someone who would presumably be in his 30s. The king himself is this, as beyond his health problems caused by smoking most wouldn't assume he's 99.
- Past Right Now: Suitsu District has been preserved for a hundred years. It appears like a 19th-century French city.
- Real-Place Background: The setting is fictional, but Badon District is heavily based on New York, and Korore District is heavily based on Paris.
- Really Royalty Reveal: Jean himself, in episode 7. Mauve hears it in a report and tells him rather bluntly.
- Royal Brat: Schwan, the only heir to the throne of the kingdom. Which is why everyone's worried about what will happen next.
- Rule of Cool: The worldbuilding seems to be based around just this. The kingdom is on a continent shaped like a bird, the districts all have their unique styles, and the language is just Japanese written in romaji. It seems like it's really just whatever the mangaka wanted to draw. And it actually doesn't take away from the complex and interesting storytelling and mature characters.
- Scenery Porn: Most of the districts provide their own distinct flavor of this, but special mention goes to the royal palace in Dowa District.
- Strong Family Resemblance: Lotta looks very much like her mother, Princess Schnee, a fact which doesn't go unnoticed by Schwan.
- Standard Royal Court: The kingdom has a fairly balanced example.
- The Stoic: Jean rarely shows a lot of emotion, at least around others. At certain moments when you might expect more of a reaction from a character in his position, like when he finds out that his closest friend Nino is the one spying on him, he barely even cares. But after watching the series for a while, the viewer can get used to noticing his more subtle emotional reactions, which can be incredibly meaningful at times like when he finds out that he's the heir to the throne.
- Tempting Fate: After the New Years speech, Those Three Girls of HQ talk about how they think "everything will probably stay the same even though it's Acca's hundredth year". The next episode, their deputy chief finds out he's actually the Hidden Backup Prince, and that's why everyone's been focused on him. Yeah, things aren't going to stay the same long after that.
- Theme Naming: The five chief officers of Acca all have names that reflect the districts they are from. Grossular from Rokkusu (rocks), Pastis from Suitsu (sweets), Lilium from Furawau (flowers), etc.
- Those Two Guys: Those Three Girls at Inspection Dept. HQ, who love sweets.
- Wham Line: In episode 7, Mauve to Jean - "You are royalty. First in the line of succession."