Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature currently requires accessing the site using the built-in Safari browser.
Only to answer the original question:
If you have a professional/ultimate version of Windows its easy.
Use search to get Windows Update -> Search for updates -> Optional updates -> Tick the japanese language pack -> OK -> Install Updates
After its installed you maybe still have to change the language under:
Controlpanel -> Time, Language and Region -> Region and language -> Keyboards and language
(Sorry for the not fitting names, but you should be able to figure out what to do)
(Procedure above is based on Win7, but should be simmilar for other Windows versions.)
On the other versions you only need some tool like this to bypass the block by Microsoft and the MUI itself which is not really to hard to find.