"Nope, just saying hello. And you're special. The others didn't have enough sense to pick up a weapon first thing. And my roommate only got attacked after he threatened to kill my child self...." awkward pause, and he actually stops and rubs the back of his head in thought, "It's a long story."

He's not sure about bowing yet though so...

"I'm Ace. Portgas D. Ace. Welcome to the Magic Kingdoms." Now he bows. He figures if she uses that as an opportunity to attack him, then he gets the answer about what kind of person she is even easier than him attacking her.