With popular restaurants, you may not be able to get a seat if you just show up. More often these days, restaurants are allowing reservations via the internet. You can reserve seats by number of people, date, and time. But sometimes your schedule changes and though you made a reservation in advance, you know you won't be able to use it. In other countries, if you don't show up at the time of your reservation, some establishments will automatically cancel the reservation. In Japan, however, it is more than just a courtesy to contact the establishment and cancel the reservation. Take the time to cancel, and do so as early as possible if you know you will not be able to use the reservation. If not, many restaurants will hold the table for you and not give it to anyone else, thinking you have a good reason for being late. If the restaurant serves only course meals or if they have been preparing the cuisine from the previous day, if you try to cancel after the meal has already been prepared, you may be charged the full amount, so be careful not to forget to cancel the reservation.