I know badminton is not popular in Australia, but it is a great sport to watch. The badminton players are so fit quick, and agile. An incredibly difficult sport to master. And it is an indoor event, and the atmosphere is fantastic.
But like others have said, i won't want to visit Japan during July or August. It is an extremely humid and hot time of the year. Even worse than countries such as Malaysia and Thailand etc
I used my Coles Platinum Mastercard a lot while in Japan and cash for smaller restaurants and shops. Easy ! (And yup, you can easily withdraw cash from the 7 Eleven ATMs)