The guy with the STUSSY jacket is on a Tomos A35 moped. I'd recognize the pattern on the wheels from anywhere The model is hard to tell, but maybe a Tomos Targa or Tomos LX. Some of the best mopeds out there.
Just went through Danbooru's entire picture library including mopeds/scooters and have come to the conclusion that this picture is the only one that has a Tomos moped in it. I give congrats to the artist for putting it in here. Shame on the rest of the moped/scooter pictures hosted here.