After Sasukes clan was slaughtered he walked into a random uchiha house and he found your mom dead protecting you in her dead arms and Sasuke picked you up and he started to take care of you as a Little brother or sister.He lied about how the clan died and he said that they were all killed by random Shinobi and he never told you that itachi existed and you and him were the only survivors* Sasuke is 13 and your 8 years old you are spying on your older brother and his team *kakashis behind you