Mr. Kinpachi in Class 3B S05 E11 New Year's Day Special

Kinpachi Sensei submits his resignation after hitting his students! In all the years that Kinpachi has been teaching, he has been nothing but patient with his students, talking out their problems with them. But this year's crop is completely different and he can't seem to figure them out. At 50, he's not a hot-headed young teacher anymore, yet why does he resort to violence this time?