Going to Japan? I recommend not going in August unless it's up north. I'd say that any large city is good. I've been to Sapporo, Tokyo, Yokohama, Kagoshima, Kyoto and Osaka now and they were all very nice. Of course, I enjoy shopping a little more than sightseeing so big cities are what draw me.
And I did go to some interesting places. Kyoto/Osaka have some amazing temples, castles, and palaces to see. What were you looking to do with your maybe-holiday?