How much is to stay in Japan for 1-2 months?

I�fm new to this so I�fm not sure if I�fm doing this right, but here it goes�c..

I�fm 22 yrs. old and I�fm planning a trip to Japan summer of 2015 and want to stay up to 30-90 days.
I want to rent an apartment with my best friend who is already staying there, so I�fm looking for apartment around for the Saitama Prefecture. Cause my best friend has family in that area and wants to closer to them, plus works in that area too.
I think I�fd need at least 4,000 for my whole trip, but I�fm not sure. I broke things down like this:

Plan ticket
Passport
JR passport
Apartment
Food
Shopping
Disneyland
An extra 1,000 for like emergencies or if I need when I go to certain tourist place or something. I know I don�ft need a visa if I stay up to 90 days in Japan.

Umm..... 4000 what? EURO? USD?

Obviously, there is a big difference between 30 days and 90 days, you'd have to adjust your budget accordingly...

Are the 4000 USD (I assume) for everything? Like, do we have to deduct flight fare from that? That would be roughly 1000 USD.

If you manage to get a short term rental apartment in Saitama idk... also a big range. A quick google seach tells me, from 320 usd without key money to 500 usd + key money + other fees. Let's say a 550 usd apartment which allows two people.

Which JR pass? 3 weeks? 600 usd.

You would have 2100 usd left for a month for Disneyland (once?), non JR transportation, accomodation if you wanna make use of the JR pass and make a long distance overnight trip, shopping and food.

1900 usd divided by 30 days: 70 usd per day

Or if you add the extra 1000 usd, 103 usd per day.

I mena you can totally save money on some days (like cooking yourself and using JR lines and doing free stuff) and using the saved money for fun days like Disneyland which are going to very expensive.

Hi,

There are too many variables in your story to give good advice based on your situation. However, I think you should consider around 60.000 yen per month for housing, 100.000 yen for a flight, 5000-6000 yen for a decent night of drinking or eating in Tokyo.

I think more importantly you should make a plan for yourself how you want to live. Like:
2 nights out per week
2 days of hardcore sightseeing
3 days a week eating out, 4 days cooking by myself
which trips in those months...

look up the prices for these things and save accordingly.

Enjoy!