Is $1000 enough for 5 days?

Hi there everyone, I was wondering if $1000 is enough for 4 nights in Tokyo. I'm fine with the airfare and that's been taken care of. I was just wondering if $1000 is enough to survive in Japan. If your wondering where I would be going, the most majority of the time is Akihabara, Shinjuku, Shibuya, and maybe Harajuku. I'm not going to like disneyland or whatever. Probably the most expensive place i'll go to is Diver City Tokyo. So I'm wondering if I have enough and I would be probably staying at a budget hotel. Also, will it make a difference if I either go though Haneda or Narita? Let me know your opinion because I'm going in August. =) Thank guys and gals! :P

I was wondering if $1000 is enough for 4 nights in Tokyo.

It depends on your standard of travel! For a low budget traveler, it will be more than enough. For a luxury traveler it will not be sufficient. Here are some basics:
http://www.japan-guide.com/e/e2410.html

Also, will it make a difference if I either go though Haneda or Narita?

Travel to Haneda can be a few hundred yen cheaper than travel to Narita:
http://www.japan-guide.com/e/e2027.html
http://www.japan-guide.com/e/e2430.html

More international flights arrive at Narita than Haneda, but if you can find one that does and is cheaper than the majority which land at Narita, the transport into Tokyo is cheaper by far.

I wouldn't call it "by far". The cheapest way to get to Narita Airport is 900 yen by discount bus from Tokyo Station, while the train/monorail fare from Tokyo Station to Haneda Airport is 620 yen.

If you don't plan to do go shopping, US$1000(101k yen) is enough to get by. you don't need to stay in a budget hotel even. I've stayed in shinjuku before, so I'll use my previous trip as example:

to get there from narita using NEX+suica combo: 5500yen
hotel: 10k x 4nights = 40k
food: 4k x 5 days = 20k (probably less since you won't be staying 5 full days, even less if you settle for cheap ramen or gyodon everyday)
suica re-charge: 3k (I never had to recharge more than this, including going to odaiba)
total: 68500yen, you will have 32500yen left for souvenirs, entrance fees to observatories etc. I'll have to warn you that 32k isn't much. If this is an otakutrip, I would save at least another $500-1000 before going.

When we go next year, we plan on converting only $500 to Yen, and using our credit card where necessary. It's easier this way if you're not to common with Yen...

cookson: japan is a cashbased society, unless you only shop at fancy malls and restaurants, I highly recommend it to bring more than $500 in cash.

I think it is fine! We booked at K-house Tokyo for 40$ a night and it was super clean and super nice. You can easily find meals at around 10$ and the subway isnt very expensive either if you walk around a lot.
You should be ok if you don't do too much shopping!