It is possible to change foreign currencies into Japanese yen at international airports, major banks and hotels, etc. However, bank counter business hours are from 9am – 3pm on weekdays.
It is possible to exchange currencies such as US Dollars, British Pounds, Euro and Hong Kong Dollars but please note that Chinese Yuan can only be exchanged as designated banks at Narita Airport and Kansai International Airport or at major banks in large cities.
When changing currency in Japan, you will be required to pay a handling fee. This fee is fairly high in comparison to fees in Mainland China, Hong Kong and Taiwan. In particular, currency exchange handling fees are high at airports so you are advised to check the difference between the handling fees of Japanese banks and those in your own country before departure and decide in advance whether you will exchange you currency in Japan or in your own country.