Are the Green cars worth the price premium?Get a rail pass (2 week).
You have to get it before you go to Japan. Gives you the bullet train/etc as well for travel between cities, and it pays pretty much for itself with just one bullet train trip.
http://www.japanrailpass.net/eng/en005.html
You can get a prepaid SIM card with 1GB data (I got mine from http://www.bmobile.ne.jp/english/note_1gb_m.html, delivered to my hotel) which I found useful for things like maps on the go and train schedules (Ridiculously helpful train timetable app: https://play.google.com/store/apps/details?id=bside.extremeambient.net&hl=en)
Visit this website lots:
http://www.japan-guide.com/
For my hotels, I booked through Rakuten (http://travel.rakuten.com/) and had no issues with any of my three hotel bookings, and it's a big brand that does lots of stuff so should be trustworthy.
Akihabara is a must in Tokyo.
Check out the BJ bars... Yeah, the castle is there, too. But not the same place as the BJ bars.This, and at least visit one maid cafe.
Kyoto is well known for it's historical architecture. IIRC, it was one of the few major cities that didn't get firebombed during WWII so there's a lot of original wooden buildings there. A big castle too. I believe it was the capital during the Tokugawa period. Too lazy to look it up. Nintendo is there too but I doubt they give tours.
Not sure what's in Osaka that's special.
for the most part, akiba is for 2d perverts and maid perverts
Check out the BJ bars...
Umm...is this another word for a gloryhole?
how does any of that even remotely compare with BJ barsHow many of these threads are we going to have? Enjoy the food. It's cheaper than America, and better. Enjoy the cleanliness and beauty of the country.

Are the Green cars worth the price premium?
This, and at least visit one maid cafe.
Kyoto is well known for it's historical architecture. IIRC, it was one of the few major cities that didn't get firebombed during WWII so there's a lot of original wooden buildings there. A big castle too. I believe it was the capital during the Tokugawa period. Too lazy to look it up. Nintendo is there too but I doubt they give tours.
Not sure what's in Osaka that's special.