To quote Saito Sensei: "If you cant move when you are grabbed it isn't martial arts". The bully on the street isn't trained in how to grab nicely, they may tense up but most likely they will just hold as tight as they can to try to restrict your movements.
Let's consider that bully on the street in a little more detail... What is he actually trying to do? Push you over, maybe? Shove you against a wall and punch you? Yank you into a head butt or a kick? Keep you from escaping while he hits you?
All of these are possibilities, but I can guarantee that his primary objective is *not* to turn your hand purple. Whether he uses fancy Japanese words to describe what he's doing or not, his target is your center, or at least some soft punchable spot along your center line.