Did Mr. Miyagi commit assault?
In the confrontation between Kreese and Miyagi, it was Miyagi who put his hands on Kreese first. Kreese asked Miyagi to leave, but Miyagi attacked.
shareKreese was harming one his students and Miyagi said 'Leave boy alone'. Kreese replied with 'Beat it slope or you're next'.
Miyagi then frees Johnny from Kreeses grasp. Kreese then attacks Miyagi coming off second best.
Now first off Miyagi was protecting Johnny so had good cause to put his hands on Kreese. Secondly, Kreese racially abuses Miyagi and threatens him. Last and by no means least he then attacks Miyagi.
It's fair to say that the only person guilty of common assault and threatening words and behaviour is Kreese. So in answer to your question, no Miyagi didn't commit assault but Kreese did.