You want go to the toilet,you see professor rengoku and professor giyuu talking each other,you pass them,and as you came back from the toilet you see Professor Rengoku waiting for you outside the class

You got a love letter and gift everyday from your secret admirer and that was Rengoku,but you still don't know that was him

Professor Rengoku waiting for you outside the class,but he doesn't want to admit it,he always looking at you secretly