This issue came up before, but it seemed to me the focus was on the content of questions and answers. I think when it comes to content, this is a site targetted at English speakers wanting to learn Japanese, and that part is working out fine. The backbone of most questions is in English, and the target is Japanese, and that all makes sense.
However, I think there's an issue in that, possibly more than most JLU communities, we are hobbled by the fact that a lot of people who could potentially provide good answers and might enjoy being a part of this are hesitant because of the English interface around all the discussion.
Using SE takes some getting used to. A person who might be able to read enough English to answer a question about Japanese doesn't necessarily want to read all sorts of instructions in English on how to get to those questions. The implications of voting a question up or down, what to do with error messages, what the badges mean... all those kinds of things are not so self evident, and the level of effort required to work them out might be too high when it requires also struggling through English.
It's an issue of friction. I know myself that even though I can read Japanese, I sometimes skim and skip over Japanese web sites that might otherwise be interesting for me to participate in just because it can be just a little too tiring to read all the Japanese required just to make the initial steps in.
It seems that full localization is not going to happen soon on JLU, so I'm wondering if there's any way we can create a FAQ, an introduction, a guide, or something in Japanese that acts a sort of entry way and assistance for people who are native Japanese speakers.
I think the scale and activity of the community is fine, even though we're not ripe for getting out of Beta status yet. I'm only proposing that we consider ways of enticing people who can expand the pool of quality answers.
So, all in all, what I'm saying is, until such a time as a user can choose their UI language, can we create an intro page and/or set of instructions in Japanese to help pave the way for Japanese speakers to put their energy into the questions and answers, and not the interface?
I'm willing to start writing such an intro/guide, but I wouldn't know where to put it...