[How about running into a hunter about Yukine's age, an older teenager with sharp, brown eyes, observing the goings-on with narrowed eyes, a hand resting on the crossbow tied to his belt.
Observing Yukine in particular, too, because hey, if he stares at him like that.... it's got to be for a reason.]
Something wrong, dude? Because you've been staring at me for, like, two minutes there. [Slight exaggeration, maybe, but.]