Yup, hit the nail on the head. He is both a) scrawny, b) a brat, and additionally, c) lacking in certain social skills.

Regardless, Kevin somehow manages to send the whole group of little girls running screaming (some of them laughing; Hiro thinks this must be part of a game, or something) before he can panic and bolt, which leaves Hiro in the awkward position of being just a little indebted to somebody he didn't make nice with a second ago.

Great.

"...Thanks," mumbled, a little reluctantly, and then. "Well. Sorry for comparing you to a bunch of bricks, I guess."