In the process of resurrecting this blog I upgraded WordPress from something like 2.2 to 2.8.6. However, when I finally got around to making a post, all of a sudden I no longer had the ability to post in Japanese. All the Japanese I typed in the WP admin interface for new posts would turn into a series of question marks upon saving, and appear live on the site in the same way.
To fix I first tried following the step-by-step instructions found at a well-referenced post at Japan It Up which explains how to go into one’s SQL database and changing those fields that have Collation to something other than “utf8_unicode_ci”. This turned out to be quite a few, over several databases — rather tedious. And it didn’t work a bit. Japanese was still being rendered as a series of question marks.
More googling turned up a post at WordPress Support Forums suggesting removing or commenting out the
line in the “wp-config.php” file. Seemed counterintuitive to the OP and to me as well, but I tried it and lo and behold, I can once again type Japanese with no problems.
Have no idea if I needed to do the first thing in order for the second to work, or only doing the second thing would have been enough. But hopefully this post will help someone similarly stuck.
For a while there, I was having bad memories of the early-ish days of (my) blogging with Movable Type when there was no easy way to input Japanese nor have it rendered properly.