How much money do I spend in Tokyo

Hi all,
I'll go Japanese Language School for 2 months in this summer. My accomodation will be homestaying(breakfast and dinner included). I wonder how much money will I spend?
I think i'll spend a lot in the first month. Because of seesighting, museums, etc...
But my spending will decrease in the second month (I think so, not sure)
So, what do you think about it?

-----
I have another question:
I'll pay for homestay. But, should i return home early? Well, I want to see Tokyo, Shibuya etc. when it's dark. So, what happen if i return home about 10-11pm?

"what happen if i return home about 10-11pm?"

Completely depends on the home. Some are anxious for your late return. Others are not.
U should ask when deciding the home.

If you are staying in a homestay, I would recommend you have a conversation with the homestay family regarding what time they'd prefer you come home.

Particularly since you are being provided with breakfast and dinner, you need to make sure your patterns don't significantly inconvenience the family (coming back late and expecting dinner to be served thus leaving late night cleanup for the family member, making noise late at night and waking others, etc.)

I sure if you discuss this up front you can avoid unpleasant situations.

As for money, if you buy lunch every day that would be about 15,000 yen/month. Sightseeing and daily travel doesn't have to be that expensive since you'll get a student discount on your monthly commutation pass and on most entry fees.

If you are on a tight budget, you should be able to get by on less than 30,000/month if you are frugal and do only local sightseeing.

Thanks for your answers. I wont be a student since i'll come with tourist visa. What do you think about staying in dormitory? I'll pay 78400 yen for homestaying per month. Actually i don't want limitations about accomodation. I have some friends in Toyko. They came Turkey at once and I entertained them. They were funny, so maybe i can stay at their home for 1-2 days. I fell into a dilemma, what do you think about staying in a dormitory?

In terms of costs alone, that price is about what you would pay for rent and food if you cooked those two meals everyday.

The question you have to ask yourself is what you hope to gain by coming to Japan.

Do you want to learn as much Japanese as you can in the time you're here? If so, a good relationship with a homestay family can help language tremendously.

If language acquisition is not very important and freedom with your own actions is more important, then staying own in your own short-term apartment is probably a better option.