Equation to Erase the Teacher

At a prestigious high school in Tokyo, the third grade D Class consists of high scoring students. This is a group with a history, as all of their previous homeroom teachers have been driven crazy within a short period of time and quit. It turns out that the students in D Class enjoy the sport of pushing teachers to the edge, ultimately watching them descend into mental collapse. They are highly skilled at this game and have yet to lose. Then one day, Tsuneo Yoshizawa appears before the D Class…