Anyway, here's the list of countries who do or don't have to take a driving test in Japan:
You don't have to take the driving test if you're converting a license from... (in fantastic alphabetical order!)
Iceland, Ireland, Italy
Netherlands, New Zealand, Norway
Spain, South Korea, Sweden, Switzerland
You do have to take a driving test if you are converting a license from...
But notably for our primarily English-speaking readers, this includes the USA, Jamaica, the Philippines, Singapore, and South Africa, as well as everywhere else in Africa, everywhere in South America, Eastern Europe, the Middle East, and the majority of nations in Asia and Oceania.