Petina, yes your friend would need to take a test IF he is resident here.
If the poster of the question is travelling as a tourist (not the holder of a foreigner registration card) he can legally use an international license that can easily be acquired in the U.S.
I recommend that he check that it allows him to ride a motorcycle exceeding 400cc.
I am the holder of a full motorcycle license for over 20 years. I was able to get a Japanese car and motorcycle license without taking a test after showing my Australian license. I believe the same rule applies to Canadians and British (?)Of course you have to take an eyesight test and provide a translation of your license (obtained from JAF as explained in an earlier post).
Despite my foreign license being for unlimited capacity motorcycle I am limited to a 400cc motorcycle. When I questioned this I was told,"日本のルール".