General FAQ, taken entirely from 境界線上のホライゾン まとめウィキ
Q: How many cours is this? Is it split up?
A: Based on the BD contents, it’s 1 cour; in terms of the novel, it covers volumes 1A and 1B. A second season has already been decided, but the number of cours has yet to be decided.
Q: They’ve been throwing around all this jargon right from the start - do I have to understand it all?
A: You can more or less play it by ear, but it would be good to learn faction names.
Q: I’m hearing “Testament” and “Harmonic Divine States” and stuff like that, but I don’t get a thing.
A: Feel free to look it up in the official site glossary (translated here) or the wiki.
Q: What’s with the “Judge” and “Tes”?
A: It means “roger” or “acknowledged.” The Far East uses Judge, everyone else uses Tes. It’s written with English characters, as “Jud.” and “Tes.”
Q: Toori and Kimi are siblings, yet are in the same class. Are they twins?
A: They’re siblings born in the same year. It’s a very rare occurence, but it does happen.
Q: Azuma’s a girl, right?
A: He is male. No objections.
Q: Ain’t Ulquiaga a robot?
A: He’s an aviation-type half-dragon. That body is actually like a shell; he’s living flesh and blood.
Q: Who’s Garcia de Ceballos?
A: He’s a famous person related to the Spanish post… Or so it seems. People who’ve looked him up in the Spanish Wikipedia say he’s just some minor guy who got a one-liner. Basically he’s in the very first part of the postal system’s history.
Post-episode 8, the author tweeted this:
By the way, García-san is a well-known person in the Ceballos region. He’s from the family that handled the privatization of the postal system, so he’s quite the significant historical figure.
Q: Why’re Muneshige’s wife’s arms so dang big? She an automated doll?
A: Her arms are prosthetic. And she’s a person.
Q: What’s “history recreation”?
A: Humankind, who once ascended to the heavens but had to return to earth thought: “Can’t we get back if we repeat the history that got us up to the heavens in the first place?”. That in mind, they have, and continue to, try this out. It’s already been around 1500 years, so the religions and laws and other miscellaneous stuff are all second nature to them.
Q: I totally don’t get what’s going on.
A: If there are any things you don’t get, please either ask it in the spoilery thread, or read the original novel. But feel free to lurk too. And if it’s something that was explicitly stated in the anime, but you just need some clarification, then you can ask in this thread and you’ll get a machinegun barrage of responses. [but again, Nihongo wakarimasen lol. feel free to ask here, or look through the AnimeSuki threads (see links section).]
Q: Oppai! Oppai!
A: Please don’t forget the thighs and ass too. [yes indeed]
Q: “New… Values!”
A: I don’t know what kind of thing you’ve awakened to, but I’m not taking any responsibility.