How much will it cost me to travel and stay in Japan for one month?

Question:

I actually want to know the cost of these two cities for two separate trips.
1. Tokyo for one month
2. Hiroshima for one month
I want an overall price including round trip plane ticket, hotel, and average amount for food. This can all be very ball park answer. Also include what an additional amount would be to see major attractions. When the time comes I will definitely be seeing a travel agency. So add a couple more thousand to the amount if you want, to much money saved is better than to little. Thanks!!! (also I'm not thinking about going till after 4 years)

Answer:

Air fare: You need $1000-1500 if you are departing from US

Hotel: Usually, you need $100 per night if you want to stay at a hotel.
If you want to save money, you need to stay at a hostel which will cost $30-50 per night.
If you want to stay at a luxury hotel, you need $200-300 or more.

Food, transportation and others: You need $50-100 or so per day. If you want to enjoy shopping, you need more.

So you need $100 for hotel and $75 for others per day. If you want to stay in Japan for 4 weeks, the total cost will be $4900 and airfare.