me and a couple of friends plan to go to japan for 2 weeks next sumnmer. We've figured out how much the plane tickets cost. I just want to know a basic cost each of us needs to raise for food and hotels?

You're roughly looking at an average of 7,000 yen a day, including Accomodation. Thats an average though and depends on where you are going to be.

You will be looking about 2,000 to 2,500 yen per night for Accomodation in a Youth Hostel or similar cheap accomodation. (The hostels here are actually really good)

Id say (if possible) work towards about saving and having about 10,000 yen per day available and you will be fine in terms of Meals, Accomodation, Travel and extras (such as snacks etc) with maybe a little left over. If you plan on buying stuff here then obviously you will need to set your budget higher.

Again the cost reflects on what you would like to get out of the trip. If you want to be staying in Capsule hotels, traditional Ryokans, eating in fine resturants etc then the cost will be much higher. I would stick to Hostels mainly, but stay in a Capsule Hotel, Traditional Ryokan etc at least once in your journey to get the experience of the culture as well.

When I travelled we kept Breakfast and Lunch cheap and cheerful and then would spend more on the Dinners etc

According to Cravez I will need 3000$ to get there...
1500$ are just the ticket. And another 1500$ for the hotels and meals? Like Cravez said...?
Man... It's expensive...

If you want to enjoy your trip comfortably then yes. Japan is overall an expensive place. My country is on par in terms of living costs with Japan so for me at the time It wasn't that bad.

Basically on Average you are looking about $85-100 per day for costs in Japan. (This includes your Accomodation and other things).

Wait wait, you're saying that 100$ per day including the Accommodation, does it mean that I pay daily for the Accommodation?

From what I saw, the hotels in Japan start from about 8000 yen per day as the cheapest. So how that small amount of money is possible? only 80$ goes for the hotel...

Youth Hostels. They cost generally between $20-30 per night. The hostels over in Japan are good and had no complaints in any of the ones I stayed in.