Japanese text in blog posts

You need to set the encodings to UTF-8.
Both PHP and MYSQL should be set to UTF-8.

WordPress setting “Encoding for pages and feeds” is UTF-8.

How do I see if PHP and MYSQL are set to UTF-8? I would think it would be by default.

Lazybuttons,

Yes, wordpress is UTF-8 by default.
But, PHP and MYSQL may not.
Please ask your hosting support. (Each hosting may have its own settings on PHP and MYSQL.)

phpMyAdmin shows MySQL charset as UTF-8 Unicode (utf8) and utf8_general_ci under connection collations. This issue only happens on WordPress software.

Please check your PHP setting by mb_get_info().
https://www.php.net/manual/ja/function.mb-get-info.php

Host claims it’s WordPress.