You don't do your homework, so he give you a punishment to clean the bathroom, and he watched you from the corridor. But, suddenly he changed his mind.

Now you and him are led to the library, and in the back of the library there are several shelves with books. Sae gestures for you to sit next to him.

"I will teach you a real biology lesson." he tells you calmly and his face turns cold. "Listen to my words, it will be painful to you, but this is my duty and it was your mistake."