This article is from the Amiga FAQ, by Ignaz Kellerer with numerous contributions by others.
ANS (Amiga Nihongo System) version 1.0, produced by SoftHouse Tecnode 102 Coupo Izumi 1-4-5 Houya-shi Izumi-machi Tokyo 202 JAPAN
and distributed in Japan by MIQ Japan, Ltd. has been released in Japan. It offers a Japanese environment for Commodore Amiga users, is compatible with Amiga DOS 2.0 (works fine with version 1.3, too), and requires at least 1MB RAM (more recommended). ANS features Japanese windows/menus (these replace the English menus), 12 and 24 dot-matrix Japanese fonts, Jinput/Joutput (both constitute a Japanese front-end processor), XEDmini (a simple Japanese text editor with built-in font editor, and can be used as a Japanese terminal), a kana-to-kanji conversion dictionary for XEDmini and Jinput, Jfilter (for viewing Japanese files while connected to an MS-DOS console), and utilities for Japanese code conversion and communication. Note that XEDmini uses pcj (Japanese version of pcd) for communications, and that one can do binary uploads/downloads while working on files). I hear that it is reasonably priced, and very easy to use.
JemTeX is a preprocessor that turns a Japanese text file (i.e., a TeX file with Japanese text) into a standard (La/Mu)TeX file. The archive (zipped) comes with the jis2mf utility along with a 24-dot bitmapped kanji font and a program for generating kanji tables. With jis2mf you can make metafont files out of the bitmapped font. JemTeX v2.0 will compile on an Amiga using SAS/C, or on a UNIX machine using gcc. This program is available at the FTP site utsun.s.u-tokyo.ac.jp (126.96.36.199). JemTeX v2.0 was written by Francois Jalbert (email@example.com or firstname.lastname@example.org).
The following are PD viewers on Aminet (text/show directory)
JIStoJi by Bart Mathias automatically identifies electronic texts written in Old-JIS, New-JIS, Shift-JIS, or EUC-JIS (as well as ASCII) and displays them on screen, or prints them to dot-matrix printers. Will run on Kickstart 1.3 and up.
jmore (Japanese more) is basically a more clone that also reads ns-kanji (Shift-JIS) text. It opens its own hires interlaced screen and requires a font handler called jFontSys to be running. The archive includes jmore, jFontsys and the wlook/16 bitmap font. However, you will also need the kanji fonts. (Aminet, `text/font/amknj16.lzh') All the documentation comes as Japanese text, so you need a JIS viewer to read the installation instructions. For your convenience, I have summarized the installation procedure below: 1. Place the `wlook/16' font in your `FONTS:' directory
2. Assign `JFONTS:' to where you unarchive the amknj16 fonts. This need not be the same as your `FONTS:' directory
3. Place the file `jFont-startup' in the `S:' directory
4. Insert the following line into your `startup-sequence': run >nil: jFontSys
5. To use execute the following command jmore <japanese.txt>
JISconvert by Dwight Hubbard is a japanese text conversion utility for Amiga computers. It supports conversion between EUC, New JIS, Old JIS, NEC JIS and Shift JIS. It also has options to convert half-size katakana to full size and repair files with ESC characters stripped. No installation required. Requires AmigaDOS 2.04 or newer.