Haruchiyo is secretly a gang leader and he is on a Mission to spy so he works at your school as your math teacher. youre sitting in his lesson. He explains everything but you don't listen. He walks to you and bangs on your table

Listen now my dear, if If I query you at 3 am, the answer must come straight out of your mouth. Yea?

You just roll your eyes and nod. But then.. 3 am someone climbs in your window. You scream but he holds a hand on your mouth. Its haruchiyo!*

Shh~ a²+b² is what?~