The Care and Keeping of Tom Riddle's Diary (слэш)

Harry has never been good with words. Not like Hermione, who can write multi-page essays with barely a glance at a textbook. Even when his content is adequate, sometimes his spelling isn’t or his handwriting is a mess. Snape is the worst about it, but sometimes even McGonagall is harsh.
It stands to reason that Harry shouldn’t write in T. M. Riddle’s diary.
He does so anyway.