Taken from a travel FAQ page I googled, I believe they won't allow it since you would stand out too much in an audience, and the audience is carefully selected beforehand with applications etc:
Audience
First of all, I have never seen foreigners in an audience on Japanese TV. On top of that, there is rarely a chance for random people to be part of it. Exceptions are large-stage music programs where tickets are sold like concert tickets. This is because the size of the audience in Japanese shows is often quite small and comes across as hand-picked. So often, the type of audience is highly controlled by the TV station. If you do not fit the target demographic, you will not be let in. The result of this is that you will just not have the possibility of finding a link on the TV station website that says "Tickets for our live shows here!". (The same is true for most US stations) You have to find a show that you like, that you will fit in as a target audience and then try to find a ticket for it. In the US, normally you can however apply or line up for a ticket directly. In Japan, it's often a two-step process: You have to first apply via postcard for a membership at the TV station's club (
such as at NHK), and THEN apply for a ticket through the membership account. There will be a lottery among all participants to get tickets. All in Japanese of course, and you will need an address in Japan to register.
So as a summary, if you are going to Japan at a specific date and try to get tickets for something recorded in Tokyo beforehand without speaking Japanese, it will be very difficult unless someone here can point you to a specific show that would fit these requirements and help you with the whole application process, too.
Additional Issues
An additional note about the challenges with being a foreigner: Even if you speak Japanese fluently, bear in mind that any coordination that needs to be done with you is a big challenge, which is of course the biggest issue if you want to participate in a show rather than just being in the audience. In a company (such as a TV company) which is not used to frequently dealing with foreigners, the staff will not even be able to call you unless you have a Japanese phone number because international calls are normally blocked on their phones. Internet sites often require addresses, local phone numbers etc to register. If you do not speak Japanese, finding someone who speaks English is a huge challenge. Therefore, since you are trying to do something that normally only locals would do, you might have the biggest chances of succeeding if you have a Japanese local intermediary like a travel agent or a friend there to help you.
I would also exclude Talent shows and the like (see comments below). The coordination with you over phone, in Japanese and the fact that you would have to go to auditions and (assuming you do not get kicked out in the first show) subsequent shows would fall out of reach because of the reasons above. I would also strongly assume that those shows require interviews and are highly geared towards local Japanese talents instead of tourists/foreigners. I know of foreigners competing in local tournaments, but I am quite certain that the Tokyo marathon has different requirements in that sense than "Japan's got talent".
