This video clip is from the BC League, an independent professional baseball league, in Japan:
Here is footage from a Japanese Shikoku League tryout:
While not often advertised, occasionally one of the tryouts in the subscription service will have scouts/coaching staff who represent the BC League and Shikoku Island League. In 2017 the Shikoku Island League players played a handful of regular season games against the New Jersey Jackals, then of the Can-Am League (now merged into the Frontier League):
Become aware of upcoming tryouts by joining the notification service here: Independent Minor League Pro Baseball Tryouts
If you need some help increasing your 60 yard dash speed times, arm velocity, vertical leap ability, hitting power or improve your muscle mass for any professional baseball tryout (or private workout) then here are some resources to help you: Resources for improving your chances at any pro baseball tryouts