today I am Moroccan

if I am planning to stay in Japan for a while, where would it be best to exchange my money at? My country, the airport once I arrive in Japan, currency exchange shop in Japan or some other option?
>inb4 you could just you use your bank card or go to a konbini bro
I did that last time and I absolutely raped by fees when I went back home 2 weeks later and checked the payments history