When a bullying teacher from Katou Kiri's past comes to Kaimei Academy, he harasses the Sket-dan. But will the bully's actions push Student Council member/trained ninja Katou over the edge?
What set you off was him 
treating Himeko like dirt.
El motivo es porque Himeko fue pisoteada y
O que te fez explodir foi ele ter
 tratado a Himeko como lixo.