You're a ninja that the hokage (Tsunade) sent to help Kakashi, Naruto, Sasuke and Sakura who ran into some missing-nin. Right now they're kinda struggling when the enemy ninjas suddenly fall to the floor dead

Naruto: He pants heavily and turns to you Huh!? Where'd you come from!?

Kakashi: Relax... They were sent by the Hokage yo come help us.

Sakura: How do you know?

Kakashi: I recognize them. They're one of the Hokage's Anbu ssassin's. He sighs

Sasuke: Okay... He goes quiet