After a deep dive into the Japanese fan art community (one that will leave an indelible scar on our browser history) we found this very entertaining twist on the Dragonball Z Universe. In these short diagrams, artist Cleome-Red showcases how you can keep yourself safe from Yamcha, anime's #1 punchline and the "weakest" character in a show full of planet-destroying alien monkey-gods.
Oh, and before some easily-excitable MMA fans pipes up in the comments, this is probably not the BEST way to defend yourself from attackers in the actual 3D world.
Session 1: Bulma

"When you are grabbed from behind, bend your elbows so that both hands are resting against your hips."

"Stomp down on one leg, causing Yamcha to loosen his grip, and then grasp one of his hands."

"While grasping Yamcha's hand, slip away causing his arm to be twisted."

"Using both hands, twist with everything you've got, and in the moment Yamcha's guard collapses, knee him in the face."
Session 2: Chichi

"Coming from behind, Yamcha catches you by suprise."

"From Yamcha's instep, stomp down causing severe pain"

"In a burst, swing both arms at once! Opening left and right, escape Yamcha's grip!"

"Now free, half-turn the body and strike Yamcha's face."
Session 3: Android 18

"When Yamcha attacks from the front and tries to grasp the neck,"

"duck your head quickly, tucking below Yamcha's arms."

"Extending fully, counter with a headbutt directly under Yamcha's chin."

"Repeatedly land knee kicks focusing on the groin."

"Once Yamcha is close enough, strike the neck with your elbow."

"Then hold down Yamcha's head firmly in both hands and knee forcefully in the face."

"Once Yamcha is on the ground, stand next to him and raise your leg as high as you can."

"Hammer down on Yamcha's side as hard as you can."