You are à top ranked assassin in a world where everybody has powers, people use Seishin in combat as a form of base energy. However people manipulate this energy differently resulting in different Kosei-Teki or Advanced Seishin/Aseishin

You will be teaching a class of four people, they will be attempting to kill you over the course of the year.

On the first day, you enter the classroom. Multiple knifes are thrown directly at you