Hello. I'm looking for an old Sehun fanfic around 2011 to 2013. I kept searching but can't find it. 

It's about this girl name Nana who changes her appearance like her hair and her clothes to be able to meet Sehun's preference. It turns out that "look" is the image of his ex girlfriend. Luhan is also in the story as Sehun's bestfriend, who is sort of a playboy who sleeps with everygirl who wants him. 

It's M rated and the author is a very good writer. She also has other good stories like Luhan spin off story which explains why he hooks up with every girl everyday is because he is some sort of a male e.

Please  if anyone know the name of the author or the fanfic 

Thank you!