I think everybody agree that spring is the best season to travel. The cherry blossom is amazing, gorgeous and unforgettable. Therefore this season is very busy. Especially the period from late March to early April is the spring break of the public school in Japan. This period is usually the peak period of the cherry blossom in southside of Japan. It is busy season.
Do not forget “Golden Week”. Japan has many holidays from late April to early May. Especially 2019’s Golden Week will be very special. The emperor will retire and the prince will take over. Please see the link below to find the detailed information about the calendar.
Summer is very hot and humid in Japan. It is not the best season to travel. However summer is very busy travel season. In Japan, most public schools have summer break from July 20 to August 31. This period is busier than usual. Especially mid August is called “Obon”. This is one of the busiest season. Many of Japanese go back to hometown and spend the time with families. It is Japanese tradition. Many of trains are booked out very quickly. Please see the link below to learn more: