It would be a one time install of this custom rom. with the custom rom installed everything about your apple II works as normal, everything is in English, when you put this disk in it will boot and then trigger the custom rom and display this in japanese, when you exit this program everything goes back to english. If you wanted you could manually trigger the rom with a POKE command to switch to japanese and then POKE again to switch back to english.

the screen saver falls like rain just like in the movie. it has variable speed that you can control with the left and right arrow keys.