On his way back into the kitchen, Chouji stops short at the sight of someone apparently sleeping at the table. "Hey, are you alright? Can I get you some... tea?"

Then he catches sight of the clothes. Oh. How did she appear right in the restaurant without anyone noticing?

Right. He's never been the first to greet anyone unfamiliar. And when he arrived, he had Sakura as his first contact, not a stranger. He answers the question without thinking. "You've been pulled into another world. So have I, and everyone else here."

Probably not the best way to break it to her.