【Key points of This Self Defense】
① When someone holds you from your back, put your hips forward.
② Next, put your hips backward fast.
③ Bend your knees and crouch down lightly.
④ Push yourself up fast like pulling your pants up!
⑤ Run away to the direction that the person doesn't stand, call the police.
By putting your hips forward and backward, you can hit at the stomach.
Also, when you stand up fast, your head would hit at the chin, and in some cases the person who got hit would suffer concussion of a brain.

Unexpectedly you can give huge damages, so that you can get a great chance to run away.
When you practice it, the above danger might occur.
Please keep in mind you need to move smoothly.