Yes you can change or cancel your reservation in 10 days after your reservation.
But we can not accept all of your changing demand.

Cancellation between '9 days before' to 'the day before'.
Cancellation fee = 50% of your normal fee that your have to pay.

Cancellation in the day.
Cancellation fee = 100% of your normal fee that your have to pay.

If the reservation day is in rain, your can change the day with no charge.