Nelli steals Lag's crossing pass in an attempt to sneak into Yuusari in order to track down her former friend Jiggy Pepper, and even considers killing Jiggy. The reason why she does this is because she's heartbroken at the loss of her sickly younger brother, and the belief that Jiggy betrayed the two of them.
Sara prevents all mail from coming to or leaving Honey Waters under the guise of being a Reverse operation, which results in the death of a man who tries to deliver on his own. But it turns out that she and Hunt had lived in a freak show, and Hunt had a dead creature's arms sewed onto him in a desperate bid to avoid being sold. When the people of Honey Waters happened upon them, Sara made up a story about Hunt being the Man Who Could Not Become Spirit in order to protect him from them, and all the other lies were necessary to maintain the first one. It helps that Sara gets a Heel Realization, leaves the money to the citizens, and leaves town with Hunt to start anew.
Chalybs Garrard, in the manga. He throws his weight around and acts rather unpleasant, such as sending Lag to the Cold Letters division for aspiring to be Head Bee. Then it turns out that Garrard had once been an idealistic and ambitious, if overconfident young Bee who'd gotten a promotion to the capital, where he ended up being forced to confront his traumatic childhood and face his repressed memories, such as his mother abusing him and killing his father, resulting in him failing the test. He then guesses that the sun is powered by the hearts of those who entered the capital, and realizing that every Amberground citizen's dream of living in the capital is based on a lie, concludes that hope doesn't exist in the country. No wonder he's such a broken and cynical man.
There's also Emil, a blind girl who was taken in and exploited by the keepers of the Wuthering Heights inn, and also formed a bond with the Gaichuu Laphroiag, using him to devour the hearts of her employers and many other people. As much as Zazie wants to stop her, particularly because Laphroiag ate his parents' hearts, he also sympathizes with her because of their similar circumstances as orphans.
Lawrence, the "Man Unable to Become a Spirit" sends a Gaichuu to the Veritably Abbey to eat the hearts of its residents, who are also part of Reverse.
In Episode 42 of the anime, Garrard crosses it by kidnapping Sylvette(actually Lag in disguise) to lure Gauche/Noir out. Once Noir shows up, Garrard plans on killing him because he thinks Reverse no longer needs Noir, and "Sylvette" for no longer being useful.
Jick Barrol crosses it by performing cruel experiments on his wife and son.
Narm: In the anime adaptation of the Honey Waters arc, Zazie makes the unintentionally amusing comment that the Cidre Gaichu's weak spot is its "butt."
Prolonged Prologue: The first chapter is extremely long for a monthly manga, so much so that it's split into two episodes for the anime adaptation, and there is only one other chapter in the first volumenote For reference, the series lasts 99 chapters and has 20 volumes, so that's an average of 5 chapters per volume. This is largely because it has a lot of ground to cover- not just delivering Lag to Cambel Litus, but establishing the setting, revealing Lag and Gauche's backstories, and setting up Lag's ultimate goals. After that's finished, there are several chapters/episodes before Lag finally becomes a Letter Bee and the story truly begins.
They Wasted a Perfectly Good Plot: Anime-only. Just what happened in the past that caused the real sun to go out? Where did the gaichuu come from and why do they anachronistically look like robots? Why is there an Eldritch Abomination inside the artificial sun? What’s up with Lag’s mother and why was she taken away from him? If you’re curious about these questions, prepare to be disappointed because rather than answering any of them the production team instead decided to pad out the show with endless, repetitive filler about the “power of heart”. They had 50 episodes (the same as the first Fullmetal Alchemist anime) but somehow ended up with less story development than most twelve-episode series. It somehow manages to rectify this towards the end, but still...
Viewer Gender Confusion: Word of God says Zazie is a boy, but many people had confused him as a girl at first, since his short hair made him seem a bit like a boyish-looking girl (like Nelli). The anime gives him a noticeably masculine voice, making it harder to confuse him for a girl.
, but many people had confused him as a girl at first, since his short hair made him seem a bit like a boyish-looking girl (like Nelli). The anime gives him a noticeably masculine voice, making it harder to confuse him for a girl.