Hello again Valerie
I don't think you'll have a problem. It's always best to check with your bank/card company beforehand if you're worried. Also, it's always good to inform your bank and credit card company when and where you are travelling so they wont accidentally shut down your account when they see withdrawals suddenly showing up in Japan.
If it puts your mind and ease, last time I travelled to Japan I didn't take a yen of Japanese money with me. I found an ATM machine at the airport (all the international airports will have one you should be able to use), and withdrew enough cash for a few days. After that, I was always able to find ATMs at a 7-11 or a post office that I could use. It was very easy