I remember a color film may be of 90's or more, where The main lead is a girl who writes every movement of her life in a diary but with little divergence. I mean she writes in the diary.. all the reactions she wants to do in a moment but she doesn't or is unable to do them.
Somehow her diary gets published and she gets so much attention. But in the end it turns out bad for her when during a TV interview she mistakenly tolls that the stories in the diary are real and is of her school and that, every character in the diary belongs to the school students. And most of the schoolmates end up hating her for portraying them in a wrong way.