Unusual words in anime

Question

This is more of a curiosity, and I'm not sure if this is the right place to ask or meta would be better (but I didn't find any appropriate tags there), but lately while watching anime with Japanese subtitles I noticed there are a lot of words or expressions marked rare or unusual in dictionaries; I see them in one anime, maybe in just one episode, then I never see them again; I guess they are used also in other places, but it seems to me they are used far far less than others. Some examples I jotted down for this question are 飼い殺し, 気に障る, 癇に障る, 親身になって, よからぬ, 回し者 and so on.

I spoke with a friend of mine, with a degree in Japanese and enough skill to live in Japan and watch anime without subtitles, and she said that she encounters a lot of words she doesn't understand, but infers from context and sound (like hearing 「てんめい」 while a character is speaking about a store, and understanding it means "store name" from てん/店 + めい/名), enough that without being able to infer them she would find difficult to follow anime.

It's a while I'm wondering about the number of words used in Japanese (or at least in anime), and I got a feeling that Japanese (or at least anime) uses far more words than English shows and English anime translations; and in Japanese there are very specific words (like 飼い殺し), and a lot of words from the same general concept (like all the ways to say "Eat", or "Speak", or "I"), which reinforces my feeling.

This got me thinking: is this something normal also for native speakers? On one hand, they are native speakers, so they are constantly immersed in the language; on the other hand, if a word is rare enough it's not easy to remember it, despite being native. I'm pretty sure there are words in my native language I forgot just because I don't get to use them often enough, and I'm sure it happened in English (which I use every day, but it's not my native language).

I found some interesting answers on the topic of non-standard or invented workds (like this and this), but they doesn't really answer my doubt, which is more on rare but existing words and expressions.

Edit: It seems my question wasn't clear, sorry about that. In English and my native language I (almost) never have to infer words meaning from the context, while I found people with good Japanese skills saying they have to do that - and quite often. Given also that I have a feeling Japanese uses more words than other languages as English, I was wondering if this "I don't know this word, but I get it from context" is something that is normal also for native speakers. I'm not sure if this is fit for SE, if not I apologize, but I wasn't able to find an answer elsewhere so I tought about trying here.

Answer 1

It is true that Japanese people use a larger number of words on a daily basis. According to one survey introduced here, the number of words needed to understand 90% of English sentences is 3,000, but you need to know 10,000 words to achieve the same level of proficiency in Japanese. As you know, Japanese has tons of onomatopoeic words, wago-kango pairs and compound verbs.

However, that does not mean native Japanese teenagers and adults heavily rely on guesswork to enjoy anime. The words you've listed as examples are not rare nor specific to anime. Average middle school students probably know all of them even though many of them don't like anime. If you have difficulty understanding 回し者 and 飼い殺し, simply you need some more work to build your vocabulary. I don't think it has something to do with how to deal with title-specific coined words like 仁星 or 海楼石.

There are a few works that are intentionally designed to be challenging even for average native Japanese speakers (e.g., 図書館の魔女), but they are exceptional. Almost no anime are like this.