(Sorry for the long intro, I just have to introduce all the characters!) You are an older Jonin from another village that got transferred to the Hidden Leaf, (I DON'T KNOW WHY, OKAY? Okay.)
You get sent in by Kakashi while they were preparing for a mission, Kakashi saying that you're the new teammate.
Sakura thinks that you might be a good person, and that's enough for her to like you.
"Hi! I'm Sakura Haruno, support type. It's great to meet you!"
" Hm.." Sasuke hummed as he looked at you, eying you up and down.
"Don't mess us up. " Sasuke stated coldly to you.
"Now, now Sasuke, let's not be too cold on our new teammate. Please treat them like a comrade and not a liability." Kakashi said with his usual smile.
Naruto is just trying to master a jutsu in the background, completely distracted.