The hair is what gets Min-Gi. Why is it moving when there's no breeze? He holds his hand up as though to try and find it, but the air feels still. There's no sign of any draft at all.

He's so distracted trying to find this non-existent breeze he doesn't immediately notice when he's about to turn. At which point there is no hiding the fact that he was staring at the guy in kind of a weird way.

"...Hello."

Maybe he didn't notice Min-Gi looking somehow. He can hope, anyway.