At risk of sounding like a terrible, horrible advertisement, I think I possibly have one thing of value to offer to the After JET section. If there are any Americans, or anyone who wants to move to America, looking to use their Japanese skills in their next job, I'd highly recommend hooking up with one of a couple recruiting agencies that specialize in Japanese-English bilingual employee placement.

My personal recommendation is TOP US, as they worked like crazy trying to get me in a job. I know it benefits them to do so, but I was amazed by how many people from their different offices were in touch with me to see if I was interested in the positions they had available. My recruiter has also followed up with me since I started my job.

PASONA
was decent, and seemed to have more interesting-sounding jobs available, but they didn't seem nearly as interested in staying in touch with me about available positions. They got me no interviews while TOP got me more than 10 (and I declined some). Ultimately, I'd recommend TOP much more highly, and I'd be glad to give you my own recruiter's name by PM if you think this would be a good route for you.

I wasn't planning to go into the work I'm doing now--"expatriate support" and human resources in a Japanese-owned company--but most of the jobs I was interested in now require a Master's degree just to get a foot in the door, so this seemed like a reasonably good alternative. I submitted 25 resumes on my own, got four or five interviews that didn't pan out due to timelines and shitty salaries, but just a few days after getting back to America, TOP was getting me interviews and serious offers. It's worth noting that I had N2 at the time, but depending on the position, you may still want to look into these agencies even with no JLPT certificate/less Japanese.

Feel free to ask me questions about the process if you're interested!