Oops, sorry! NHK Easy xD I’ll edit my post, haha. (I’m too used to calling it NHK in my head.)
Just wanted to throw in a link: Japanese Pokemon Sun stream #1: Learn Japanese! ポケットモンスターサン - YouTube
They are playing Pokemon Sun in Japanese and explain a lot of vocabulary and grammar points. On the channel they also play other games in Japanese. I think that’s nice to check how much you can understand without the explanations 
Because it wouldn’t work. Learning decontextualized grammar and Kanji without practicing reading will not allow you to be able to read. Granted, with those tools your learning curve would probably be a lot faster, but the main thing that makes you better at reading is reading.
I wasn’t being all that genuine when I stated that. xD Guess that didn’t come across right. I meant to emphasize that I found it a bit silly to wait. If you’re excited and have the motivation, there’s nothing stopping you from trying sooner rather than later.
Not to mention that you need to have reading skills in place to pass those exams. 
For anime, if you’re aiming to watch without subtitles, I would say you have a ways to go before you could watch a lot of those series. WK won’t really help much with series like Shokugeki no Souma and Restaurant to Another World due to their specialized detail into food terminology. Note I have not read any of these manga (though I am reading Sword Art Online and Restaurant to the New World in light novel form currently), so I cannot gauge the reading difficulty.
Shirokuma Cafe, Poke’mon, and SAO (until GGO & Mother’s Rosario) could probably be managed without subtitles somewhere around level 20, depending on your grammar. You’ll miss fine details and definitely any word-play jokes, but you’ll get enough from context to get what’s going on. If you’ve already seen them, even easier. However, once Alicization gets animated, the Japanese is going to get crazy hard, as the sci-fi meter gets kicked up a ton.
Black Butler, Ancient Magus Bride, and Death Note are easily going to be level 30+, if not higher. They rely heavily on dialogue, and context is much harder to grasp do to the characters “doing” less while speaking. In order, Ancient Magus Bride is probably the easiest, while Death Note is probably the hardest. Ancient Magus Bride does have a few characters with some archaic flavor to their verbal style though.
For games, Persona will be a monster to translate before level 30 without a doubt. Grammar, of course, makes a huge difference in this. As @RysingDragon mentioned, games that cater to younger audiences, even in the Kanji + Kana format, have many words that are written in kana despite having jukugo, meaning you need external vocabulary resources and/or need to take a lot of time for research.
Rhythm Heaven should be quite simple to play in Japanese, as, to my memory, almost all of the gameplay relies of visuals and not written instruction. With an E-dictionary, you could probably start this at any time to force yourself into not being able to use English while not overloading yourself.
Touhou is another game that should be fairly light, though verbal styles could cause minor hindrances. Due to the fact that most of the text is dialogue, it’s not that difficult to read. As for Spell Card names, well, just use the wiki to memorize those. 
Fire Emblem I think is probably the most difficult of the games you listed to translate. Without external vocabulary resources, you’ll probably want to be in the 40s if you don’t want to probably quadruple your necessary playtime for reading.
Listening to music while reading Kanji & English side by side is a great way to expand vocabulary, especially if a romaji go-between is available. While songs often take many more liberties in regard to grammar, lyrics are usually more straight-forward than long sentences one can find in novels or games. Not to mention, singing along while listening can give you some natural experience into producing the language while learning. 
I would try using Animelon, which I know for a fact has both Shirokuma Cafe as well as the first three of the SAO series. That site allows you to watch anime with a choice of English, Japanese, and romaji subtitles, and you can even click on the words to pull up a dictionary! Seriously, it:s amazing.
Good luck, and 頑張って！
Hard to answer just based on WK levels, since actual interacting with Japanese extends faaar beyond the site’s singular focus on kanji. It’s much easier to offer answers based on the more all-encompasing JLPT levels, from which you can extrapolate the corresponding WK level, in terms of how much kanji you’ll know to aid smooth reading.
In the 20s and at an overall ～N3 level, you should be able to comfortably, if slowly, interact with any children’s media and get the gist and most details without a horrendous amount of look-up. (Though the first time you truly start reading things on your own, doing quite a bit of look-up is inevitable.) You should be able to interact with simple adult material more slowly, often getting the gist but maybe not all the particulars.
That doesn’t mean you’ll be at a level to, like, provide pristine translations for someone else. But you’ll be at the level to comprehend them on your own.
For anime: I recommend picking something you’re familiar with and turning Japanese captions on, if you have that option. Knowing the overall context in advance and being able to follow along with any kanji you know helps immensely and makes for good training wheels.
For manga: Again, the more familiar, the better, at least early on. You’ll spend less time second-guessing your own understanding if you’re familiar with the work in translation, and it might help you suss out the hows and whys of less familiar grammar. But don’t be afraid to check out new stuff or stuff without furigana too. You have all the time in the world to sit there and decipher print, so challenge yourself. I got through quite a few adult-oriented manga, and some for kids without furigana, even in the high teens/low 20s here. There’s more look-up, but if you have a grammar background, you’ll be surprised how much you can follow.
Source: My own interactions with print and visual media at about an N3, bridging into N2-prep level over the past year.
And when in doubt: Try it. See how much you can get and how long it takes you. You might be surprised by what winds up being a good use of your time.
Thanks, everyone! It sounds like I’ve got a ways to go, and even then WK won’t be a complete guide. I’m willing to put in the effort, though. I’d like to review a couple key points I’ve gleaned from the answers so far, just to see if I’m on track:
- WK is focused on Kanji, but I’ll need to know a fair amount of grammar and general vocabulary as well
- Some of the items I’ve listed will be harder than others (which I think I saw coming)
- The best way to gain practical knowledge of Japanese as a language is to just practice reading/writing/listening to/speaking it. (Quantity > quality)
- Even if I don’t understand most of what’s being said yet, I can still learn a lot from what little I already do
Does that sound about right?
unforgivable >:)
@nerdymartian Thank you! We used this site in my undergrad Japanese courses and then I lost it. And to @The1AndMany, try to stick to the n+1 principal. Don’t shoot for something way out of your league, try to just nudge out of your comfort zone. And don’t feel bad if you struggle. I majored in Japanese and am having to basically start over completely. It’s very frustrating when I think about all the time I put in years ago, but if I look at it as “Am I better today than I was yesterday?” then I feel much better.
If think it’s more “if I don’t understand all of what’s being said”. As previously mentioned, the sweet spot is n+1. If you understand 10% of every sentences, you’ll barely learn anything and will get demotivated.
my experience has not been this. When one starts reading, there is not going to be any interesting Japanese text you can understand all or even close to all of. I have found that there is alot of value in reading a manga or a book even if I can only understand 1 in 5 sentences. That being said, the point of doing this is to get better. With almost all the material I have tried, the first time I go through it, I get about 20%, The next time 40%, the next 60%, etc.
It’s important to realize that any text you read is going to have a large range of sentence difficulty, so in a given text some of the sentences will be +1, others not. I read the ones I understand, the +1, and don’t worry about the rest. I have found that as I study more grammar and vocab and get more experience, when I revisit something the number of things in those catagories (understandable, +1) steadily increases.
Hello.
To this I would add that with a good N2 level of Japanese, you could read and understand most young adult novels (that don’t have too much speicalized vocabulary). For daily life adult novels, you could certainly understand 80% of the story with a dictionary in hand.
** speaking from experience
Though I cannot say anything for WK levels, at a low Japanese level I would pick and try to read Doraemon & Pokemon as they were intended for Japanese children and the grammar is not too intense.
I think we’re saying the same thing: focus on n+1 sentences.
From my personal experience, working on understanding 100% of every single sentences is not worthwhile, especially when you have to search 10 words and 2 grammar points.
But I disagree that any books will do. It’s nice that you can go through the same ressource several time, but I personally get bored and can’t stay interested if I understand 20% of the story. Plus if the content really interests me, it will be even more frustrating and I’ll end up switching to an English version.
I hear ya. I think the real answer to all this is do whatever you want to do as long as you are reading. I think the OP was asking a sincere question though, and I think it would be a disservice to them if they walked away with the idea that if they were trying to read something and only understood 1 in 10 sentences that they were doing it “wrong” somehow. Understanding 1 in 10 sentences with the help of a dictionary was certainly the level of my understanding when I tried to read my first manga, book, song lyrics, etc.