I came across
this story at HPFF recently and thought it'd be interesting try out.
Then I started reading and was shocked.
It sounded like the first chapter of This Longing. Not exactly, but damn close.
My story starts with Minerva on the train, meeting with the prefects and finding the Head Boy to be the one person she didn't want it to be.
This other story has the same thing. :/ The male OC is both sarcastic and apologetic and pretty full of himself. Not too unlike Grimm. The endings of the chapters are very different, but reading those first half was rather like reading a warped mirror image of myself.
It's not plagiarism, of course, but I'm enough of a megalomaniac (after all these years) to read mine and like it better. :P Just had to share that, sorry.