Cobra Kai

The original trope-codifier. John Kreese runs the dojo like a boot camp. Among other things, we see him punish a student who falls out of sync with the others by making him do 60 pushups on his knuckles, and has Bobby Brown (black belt) spar Robertson (green belt), which anyone will tell you is a pretty unfair fight. In the All-Valley Tournament, he orders Bobby to put Daniel out of commission (which Bobby only reluctantly agrees to do so), and has Johnny Lawrence sweep the leg.

Example of:
Thug Dojo