Some replies already in this thread to my question but still I would like to ask.
I post it here so that someone in Google finds this too.
I booked a room from Japan with Advance Purchase 30 Day rate four days ago.
A stay will be after couple of months. Cancellation fee below is one night rate inc. taxes.
I thought it was a advance purchase/ prepay rate, but still no charge to my credit card.
Do they charge total stay at the time of booking or later?
Also I thought that my rate is not possible to cancel.
If I cancel is the fee 1 night or total stay amount?
I will not cancel it anyway, just want some info about this rate.
Rate rules for my booking are a bit confusing:

Rate Rules

Advance Purchase 30 Day rate, see Rate Rules

Canceling Your Reservation
You may cancel your reservation for no charge until Xxxx XX, 2014 (2 day[s] before arrival).
Please note that we will assess a fee of 22,210. JPY if you must cancel after this deadline.
If you have made a prepayment, we will retain all or part of your prepayment. If not, we will charge your credit card.
This fee equals 1 night of your room charge plus tax (for the first night of your reservation).

Modifying Your Reservation
Please note that a change in the length or dates of your reservation may result in a rate change.
Your current rate may be available if your modified reservation still includes:
A reservation made 30 day(s) before your expected arrival.
Eligible charges from this stay will be credited to your Marriott Rewards account.