Hermione is Harry's Boggart
Instead Of Harry's Boggart Being A dementor It's Voldemort Torturing And then Killing Hermione as he begs him to stop as he is restrained and forced to watch.
The reason why Harry's Boggart is just Hermione and not all his friends is Because he is secretly in love with her.
But he knows he is not good enough for her, and he thinks she would never love a freak like him that way( The Dursleys abuse has affected him into believing he can't be loved)
Harry's Boggart Becomes the Biggest rumour in the school, It only took about half an hour for everyone in Hogwarts to know that Hermione Granger being Tortured and Killed is Harry Potter's Boggart.
Hermione confronts Harry about his Boggart and Harry In anger shouts at her The reason why she is his Boggart is because he is madly in love with her and he can't stand the thought of her getting Hurt.
Hermione then does something surprising and kisses Harry before telling him that she is in love with him as well but she always thought he saw her as a sister/Friend.