Having lived in Japan a year and a half with all sorts of wear. I would say that American semi casual is acceptable. Grub-wear is not. If you have heals and you wear makup and do your hair, the gals will see you as equal. Being yourself is welcomed by those who are willing to open their arms to strangers. And that is actually not as common as it seems. It takes much time to make friends there. Sometimes you think you have a friend and you don't. High spirits and a focus forward, with courtesy, modesty and respect wins friends in Japan. Having common topics to talk about is also a plus in all places. A suit is stiff, but class and those magazine links above are great. But keep in mind that Japan is a country with many tastes and values. It is difficult to understand the standard, when really, the standard was invented by The GAP and Le Chateau... overstatement. But the US, Australia, France, and England are large influences in fashion.