Just added multi-byte (Shift-JIS) support to text processing, and also added to ability to render bitmap based Japanese fonts. It was relatively easy to do, approx a week of work for me.
However, it is far from ideal. Ideally, UTF-8 support is recommended, instead of Shift-JIS, to have better possibility to create versions for more languages. Also, current Japanese build requires mission files written in Japanese. Ideally, support of multilingual mission files is recommended.
Also, font size is too small. It is readable, but very minimum readability. Ideally, larger font size (including English font) is recommended. But it will be a big change.
I'm dreaming to see UTF-8 supported SCP version with using bigger font for 1024x768 or higher resolutions in the future.