The best way to buy an air ticket is to use the cash voucher shop successfully. It is cheaper than buying normally, so if you buy a gold certificate shop is good. On domestic flights, it is divided into two groups, JAL and ANA, so please narrow down to either one and make a mileage card. If the destination is Hokkaido, Fukuoka, Tokushima, Miyazaki, Kumamoto from Haneda, there are even cheaper airlines. Tickets are available on the website of each company. As soon as you make a reservation it will be cheaper. However, we sometimes sell excess seats cheaply. Also, there are times when it is cheaper to make a specific flight on a specific date. Besides, it will be cheaper for two weeks before and after the birthday. There are restrictions on cheap airline tickets, such as the change does not work or the refund fee is high, so it is better to check well. Please think it well and use it. It is convenient because it can be done easily by using a credit card in the sense that it takes time and effort. It is very easy without having to go to purchase because you can purchase / book the procedure in the house. Although I can not see the actual ticket, I will go to the airport the same day and use a credit card at the check-in counter to get a boarding pass.