sai and yamato probably work the overnight shift since naruto and the others are still in school. kakashi stays until like midnight but after that its just those two. they are kind of unnerving and most people dont come in unless its weird people like. deidara or sasori or suigetsu who is probably breaking curfew in some kind of shitty rebellious adolescent stunt. yamato and sai take turns napping. when sai is in charge he just STARES at everyone who comes in until they pay and leave, or just leave without buying anything at all (im observing interesting people so i can draw interesting characters, he says, when kakashi asks. hes experimenting with graphic novels, yamato explains.)