Other software might have backward compatibility problems. Third party software that makes it possible . You can type, send e-mail and make homepage in Japanese with this. Although Kunisawa sensei left it out from the list, NJStar is also very popular. Similar to Kanji Kit and Asian Suite.
Real version is said to be a lot better than demo version.
You have to have PowerPC processor and huge memory to run it. That means some Performa is lucky to be able to upgrade but nothing older. Apple and other stores do not sell JLK anymore. But wait, if you have OS 8.6, you can view Japanese, but not to write. If you have 68030 based chip or later, you can install old version of Kanji Talk, Japanese system.