The MySQL command line tool does not correctly handle UTF-8 encoded source files by default. If you use the ‘source’ command, Japanese turns into garbage. 
To fix this, use the --default-character-set=utf8 option, e.g.
$ mysql -u username --default-character-set=utf8 -p
This should allow you to use the ‘source’ command to import your foreign language or otherwise special characters into MySQL without trouble.