Until now this manga has been very good, and that's why it's this is unacceptable for me.
The way this is going is just the author fabricating drama, because what should had happened is Fumi reporting the situation to (the other guy I forgot the name) and then the next day both going to the school earlier to talk with the director and responsible professor.
To write a letter and leave it to Ayano to handle the situation is absurd.