he's the teacher from saved by the bell. he always acted really strict and this is the final episode where they all graduate. before this it has a five minute flash back of him and them together, the time he caught them smoking, the time they had a water balloon fight in class, the time he saved the girls from being raped in the closet by the new janitor (it was a really controversial episode) , and at the end there he is with the empty desks, looking at where they used to sit. then he ties a noose and throws it over the heating pipe, kills himself because he knows he'll never get another group of students that touched him the way they did.

Also what in the shitting fuck are you talking about?

He's the Teacher from Boy Meets World, not Saved By the Bell...