Naruto has a sister?! Namikaze Hotaru! - Sasuke Love Story

Her Name is Namikaze Hotaru

She has blond hair just like Minato (her father), her personality is just like her father as well, but if you get on her bad side she is like Kushina (her mother).
She also has blue eyes and whiskers like Naruto.

Hotaru instead of growing in Konoha she came to a different world, where she was given to another family after Minato and Kushina died after sealing the Kyuubi inside of her and Naruto, since the Third Hokage thought it was best for her to live in another world. That because she had Namikaze in her name and people would try to get her and kill her since she was the daughter of the Yellow Flash!
In this world she is known as Layla, her "parents" are afraid of her since they know what she has inside of her, they don't treat her badly, but they still react with fear towards her.
She doesn't know who she really is, however she feels that she is different, she just doesn't know why.
She is going to have amazing teachers, including S-Rank Criminals and the three great Sages! (yes, Orochimaru included even though he's creepy). But the one who's going to teach her from the start is Uchiha Itachi ( it'll be explained later in the story why him).
She will also find love and will have her heartbreak.