Panic in High School (1978)

A parable about the inefficiency and anachronism of the Japanese educational system, which places an unusually large amount of importance on cramming for university entrance examinations, Panic High School is about the suicide of a high school student and its ensuing fallout at his school. When one of his classmates becomes frustrated with the math teacher's lack of sensitivity to the suicide, the student steals a rifle, returns to school, aerates the teacher's chest and then holds members of his class captive. This leads to an aggressive standoff with the police and lots of shots of his parents crying and bowing in shame, totally mortified.

Unfortunately the movie Panic in High School is not yet available on HBO Max.