Gotta share a few things I learned while in Japan. I'm a European in my twenties and went there to study Japanese for some time. Anyway, girl-wise, Japan was everything and a lot more I could ever hope for!
I got invited to dates by 11 girls and I kinda had a relationship going for a few months with one of them, meaning about 10 dates within 4 months. My goal wasn't really to have a lot of sex because the circles in my town were too small and I wanted to be the gentleman everyone took me for. Now I really wished I had tried more but I'm young and gonna go live there so no problems. In my country I'm like a 7. I'm not that chatty or funny either but I smile and I'm the nice-guy. This is usually a bad combination but ohhh does it work in Japan.
The girls I went out with varied a lot although the age was almost always a couple of years younger than me. I had a super-loli type, seriously she was like half of my size with amazing tiny hands and really small boobs. Also went out with a model who appears in TV too. Not a popular channel but anyway, she was really beautiful. I got everything from between those lines and only one of them was not really good looking.
1. When you go to Japan, look for some local cultural exchange groups. You'll meet a lot of girls who usually really like foreigners and these groups organize parties and events too so you'll have something to fill your schedule with.
2. Don't be afraid to be near the awesomely hot girls. If they fall within the 'good-girl' category they haven't been with weird yakuza-people and the normal Japanese guys are too afraid to get close to them. Therefore, they are fair game for you.
3. Almost any city is better than Tokyo in my opinion. The less foreigners they have there, the better.
4. You ARE going to be treated like a Hollywood star if you're even remotely good-looking and are in the right place. I got some serious trouble believing this at first because at Friday nights the hottest girls in the bars came to talk to me and the hostess/gyaru type girls hit on me on the streets. And if you're from the northern Europe I consider you the most lucky. Just my opinion.
5. Find some Japanese guy-friends too. They can get you into interesting boobie-bars and hostess thingies, even soaplands, the good ones you wouldn't get in by yourself.
That's what comes to mind.
In conclusion, before my trip I was kinda sad I wasn't born a Japanese. Now, I couldn't be happier to be a European
* Oh I forgot to mention that I DO speak good conversational Japanese. My skill is about JLPT N2 level, if that tells something. That's where you wanna be at least if you intend to keep the conversation going until the hotel part of your date.