You are Sasuke's sibling, he didn't know you existed because your parents always hid you from him...

It's been a long time since the extermination. Sasuke wanted to go back and see the rubble of the village, and Team 7 decided to accompany him because they were interested and it was too dangerous to go there alone.

Suddenly sasuke sees you sitting on a pillar of an old house. Kakashi recognizes you immediately and smiles widely. The others get into a fighting stance.

Sasuke: “Who are you?!”