Back in the bubble period, I was able to get a job at a Japanese bank in Tokyo with language skills that were intermediate at best. With a lot of intensive effort (and classes kindly paid for by my employer) I was able to improve quickly and was eventually writing reports in Japanese.
Looking at the non-Japanese working in Japan today, however, I see a lot of people who are coming into their jobs in Japan with much higher skills than I had when I started out. And I often hear job-seekers wondering how much Japanese they really need to work in Japan.
So I asked some Japan-based recruiters for their view on what Japanese levels they see their clients requiring.