World Currency: Shibuya branch
If you’re looking for the security of a bank-style currency exchange facility, head to World Currency on the 7th floor of the Daigai Building. It’s easily accessed from the Hachiko Exit of Shibuya Station and just a short walk across the pedestrian crossing outside.
World Currency is one of the most famous networks of foreign exchange facilities in Japan and operated by a subsidiary of the Bank of Tokyo. While it supports a lot of currencies (19 at the time of writing), the rates are not as good as you can find elsewhere and you will need to bring your passport with you. Their opening hours are also limited, from 9 am to 7 pm Monday to Friday and from 11 am to 5 pm on weekends and public holidays.