You can write Japanese script even the computer has no Japanese input
software installed. All you
need is internet connection to use this page.
Put the IME on (make it blue)
and type in any romaji, and press space key. You will have a pull down menu on the web page. Select the right one and press enter key.
Even your machine OS is English Windows 98, you should be able to write Japanese script. Some pupils may have this system at home.
For Windows :
University of Redlands has detailed information on how to do this.
For Mac OS X:
There is nothing to do. But if you have problems, go to System Preferences and change the order of language preferences and add Japanese Input.
If you click +, the menu will expand. Try to expand the folders until the folder which does not have sub-folders underneath. And click the folder name rather than click a single post.