Exchanging foreign currency to Japanese Yen, JPY was a nightmare. Exchanging money was possible at banks(not all but only designated branches), some of the post offices and some hotels before. Then, all currency exchange were operated by banks but the regulation has been changed and non-bank can operate too.
Therefore if you forgot to exchange at the airport, your next chance was to do at the bank or at the post office. However, banks are open till 15:00 and post offices till 17:00, both of them are closed on weekends. Then, Japan does not accept credit cards as much as in Europe. Metros, buses, admissions, and vending machines accept cash or contactless smart card(i.e. SUICA) only.
Due to rapid increase of foreign visitors to Japan, exchange kiosk is ideal solution for foreign tourists who need to exchange the currency to JPY in the evening, during the weekends, especially in major tourist destinations.
This exchange kiosk allows 12 currencies to exchange to JPY, including EUR and GBP. This kiosk is mostly for Asia tourists and it is convenient for them to exchange their currencies directly to JPY, which means they do not have to exchange to USD or EUR from their currencies before arriving in Japan and exchanging EUR or USD to JPY.
Unfortunately the kiosk does not accept other European currencies such as CHF, CZK, HUF, PLN or RUB, but currency exchange at airports mostly accept these currencies too. However, the exchange rates are not good and you have less chance to exchange these currencies in Japan. Therefore I recommend to exchange from your home currency to JPY before your departure at your local bank. However, if you found EUR or USD at home, take them with you to Japan. May be you need to exchange at the exchange kiosk.