Sick of trying to remember Japanese or which buttons are which? These stickers are available from Barry Anderson for $20. They are a good quality thin plastic sticker pre cut to fit the appropriate button, you can't even tell they are stickers.
For a tip on the best way to put these on fill up a water spray bottle with water and put 2 drops of detergent in, then shake the bottle and spray the buttons. While the buttons are wet put the stickers on they will be easy to move to ensure you get them straight, then you will need to leave them for about 12 hours to dry.