Because the Japanese language has three different kinds of characters, the Japanese Word Processors (JWP) can be viewed as an separate category in the MSX universe.

The most elaborate JWP use the MSX-JE system, but there are also JWP without this system.

Almost all JWP require a Kanji-ROM Level 1 (JIS1) or Level 1 + Level 2 (JIS1 + JIS2) to be operational. Sometimes the equivalent of a Kanji-ROM is included on the tape or disk with the Kanji Word Processor.

The most advanced Japanese computers or cartridges have one of the Kanji-Roms built-in.