It's the markings that catch Naoto's attention first. The fact that neither of them is in their home village makes her more cautious about approaching--she'd feel safer in Uzushio--but the curiosity doesn't stay well contained long, and the scroll the stranger was looking at was interesting too.

So Naoto approaches. Not even her sandals make her actually taller, but she stands straight, almost tense from it, and intentionally speaks a little roughly. She's either honestly just that tough, or trying too hard.

"What have you got there?"