I think the title should rather be "working as a foreigner in the entertainment business in Japan".
In this post:
How to get jobs .
The highest point your career can get.
Obvious scams (apart from the agencies with "payment issues").
After appearing in one TV show in my home country I decided to try my luck in the Japanese entertainment (as I was heading to Japan for another job anyway). All in all, for mamas and non-mamas, it can be a nice hobby or a side job (or maybe even a main job- although questionable), but please read carefully the following post. Below I've written information about my personal experience + things I witnessed from others.
Type of Agencies:
If talking about real agencies (and not the so-obvious-scams), there are two types of agencies in Japan. Regular jimusho (offices) hiring/scouting Japanese "talents" and the gai tarento jimusho (translating: foreign talents' offices) hiring and dealing with foreigners.
Regular jimusho (think Watanabe production, Burning, Horipro, etc....Or even some tiny less known ones):
I honestly don't know any foreigner who managed to get some gigs from a regular agency (especially the big ones). Your amazing Japanese level doesn't even matter to them. They simply don't want to deal with foreigners. They might deal with "ha-fu" (children of international/interracial couples), but that's about it. And even if you find some small agencies that will sign you up- they will probably never call you for a job.
Gai tarento jimusho (the ones hiring foreigners):
Now, the gai tarento jimusho agencies on the other hand, will hire every and any foreigner they manage to lay their hands on. And frankly, it doesn't matter which agency you choose- they are all connected to one another. Basically, there is this huge agency called IMO (among the ones I've worked for) and once in a while its managers leave to open their "own" agencies, but (especially after reading this , *thanks Sophelia), I'm pretty sure they are all affiliated.
If you've read my experience working as a freelance/contract journalist you already know that it can be pretty hard when it comes to demanding your own payment. But, honestly, you won't know what's "hard" until you try getting your earned money from the gaitare jimusho!
***The following is true to the one agency I was dealing with. I guess there must be honest and good agencies out there, too. I just happened to land this one because it was the biggest (so I supposed I can trust them).
First of, when you come to sign up, they will tell you you must open a new bank account with the bank they are comfortable with (sounds like something dirty already), but OK. They don't check your visa status (which is required by law, but there's a perfect explanation to it- just keep reading), but OK. There isn't any contract to sign and then they tell you they just pay (sometimes cash and sometimes to the bank) 2 months after you've done the work.
In reality. they don't pay. They don't even intend to pay.
They actually hope to hire aspiring naive actors who come to Japan without the working visa so that they can exploit them until the very last drop, cash in 100% of the profit to themselves and live happily ever after. And the poor foreign actors? Oh, they can't complain because unless they have a working visa/spouse visa, they are not allowed to work. Meaning, by doing the TV/CM works they are breaking the law thus they can't and won't complain to the authorities.
Then there are the foreigners who do have proper visas, but they, too, can just dream about getting their money. Why? Because they are foreigners. Those agencies count on the fact that their basically free labor doesn't understand enough Japanese and the Japanese system to know how and who to complain to. They will keep feeding you stories of "wait a little more", but unless you threaten to go to the labor union, they won't pay you. Ever.
The good news is that when and if you do get paid by appearing as the audience, playing an actual role or being an extra, you can expect to earn 100~250$ per few hours to a day of work and few thousands $ if working on a CM/Video clip.
How To Get Jobs/Sign-up:
Basically, you can just google "talent agencies in Japan" and choose whichever you want, or even go to all of them. They don't ask to represent you exclusively and they don't even present you any contract to sign.
Once you come, you will need to fill-up their application form (which sometimes cost around 10$/1000yen, but many will take in your application without telling you to pay. In my opinion, you should NEVER pay). Then, they take your photos (a close-up and a full-body).*Be sure to look your best as they can't care less whether you turned out looking like a mashed potato. You can email them your "good photos" all you want- it's unlikely they will bother using it.
That's it. Go home and wait for their call.
It's unlikely there will be any audition (well, obviously if you really suck on your first job they might not call you again, but you don't need an outstanding talent to keep getting jobs). I would also advise you to write as many skills as possible on the application form because that list (and your looking- which, doesn't have to be good- just fit into whichever role they'll need you for) are the only things you are judged on.
I have played several roles with text and all, but was never actually auditioned to them. Thankfully it turned out all good and the directors were happy but I wonder, what if they cast someone who seriously cannot play at all?
Now, if you still aspire becoming "Big in Japan's Entertainment", here is what you can hope for:
Assuming that you are chosen to be on some show/CM/clip based on your looking/previous work or even just because you were free to attend, prepare to accept the fact that you would probably have more chances getting into Hollywood, than becoming a real celebrity on Japanese TV.
The market for "foreigners" in the J-entertainment is limited to the followings: extras for TV shows filming stories about foreigners/foreign countries, supporting roles for TV shows filming about foreigners/foreign countries, main roles for TV shows filming about foreigners/foreign countries, audience in a TV show which is filming about foreigners/foreign countries and finally CMs that occasionally want foreigners because they are filming to/about foreigners/foreign countries or because "having a foreign face in the commercial is cool".
It's quite natural...I mean, you don't have other countries writing movie/drama scripts about Japan and filming it with all-Japanese actors, in Japanese language, right? Therefore, we can't expect Japan's entertainment to have enough space for foreigners :P
Even if you get the "main role" in TV shows that are filming stories about foreigners (shows like; "unbelievable", "123 Best House", "Gyoten News", etc, etc). you get max several minutes of face time per episode. What's more, your voice will be dubbed over by a Japanese voice-actor (because Japanese don't like reading subtitles...?) and your name will never appear on the ending credits.
I appeared a lot on those shows and because they are really popular I did get the occasional "oh, I think I saw you on TV the other day" comment from people I had business contact with/new friends, but you can't expect having random people randomly walking up to you to compliment (Japanese don't do it in general) and forget about establishing fans. Yes, I'm talking about the mainstream shows on the biggest channels here! I got to meet foreign actors that regularly appear on those shows for years and even decades(!), and while they are somehow able to survive salary-vise, they got no "fan-clubs" (forget about longer TV time per role/merchandises/official websites backed by their agents/etc) and nobody even knows their names (as I've already mentioned, it never appears in the credits).
*There are a few foreign TV personalities who are actually quite famous, but they gained their popularity in the 80s...I don't know of any current "big" non-Japanese celebs in Japan.
Aside from the non-paying/delaying payment agencies I've talked about above, there is even worse type: the type that takes your own money and you never (probably) hear from them again.
If you walk in Shibuya/Harajuku/Shinjuku you are likely to be approached by a "scout". While I heard some stories of Japanese models/singers being scouted on streets by top agencies/magazines, I think it's really rare/complete bullshit. Mostly, you will be approached by a fake agent (or agent that doesn't intend to give you any jobs) that will then invite you to their office (probably even temporary one), show you all bunch of magazines claiming the girls there are from his agency and promise you are the next big thing! Then they will go on to tell you that a) you need a professional portfolio- something only they can do for you for a heavy price, b) you need to take their acting/dancing/modeling lessons- also which cost.
This type of scam is not only in Japan, so be careful if you try your luck in other countries, too.
Luckily, I knew about it before starting working in the showbiz, so I never fell prey to them.