i went to japan last year in August for 3 weeks doing the temples and sights tour. ah lets see, my advice is don't rent a car whatever you do, take the trains everywhere. If you're short on cash don't go, because you'll probably spend $1000.00 a week minimum. If you need a cheap place to stay, they have these business hotels that rent single rooms for about 600 - 800 yen ($60-80) that basically have enough room for a bathroom and the bed but are clean! lets see, if you're staying in Tokyo and want to check out the night life the Roppongi district is good. there are a few english speaking bars there. As for the clubs, most of them you pay by the hour but can drink unlimited during the hours you've paid for. Also almost none of the clubs are street level, you'll have to check out the different floors and the different clubs. i think we went to club 911 and that was fun, met some british strippers and they were pretty chill.
hmm as for food, their american breakfast sucks, if you like fish always go with the japanese breakfast at the hotels. The Katsu burger isn't as good as it looks (you'll know what i'm talking about) You'll have to try these types of resturaunts: Yaki Nikku (japanese bbq, kobe beef), their Unagi houses (an Eel steak house, don't get freshwater eel), their pork broth ramen with roast pork and garlic is to die for! and the sushi is amazing (I recommend the "Toro"
a must) One last thing, and this will absolutely blow you away, go to the supermarket or farmers market and buy a box of grapes, now they'll be $14 for a small box, but you'll never taste grapes or fruit in general this good anywhere else! I promise you! hope this helps