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I don't do much manga. If there's something wrong, please tell me. biggrin If it's okay, tell me also please

The guy's neck might be too thick (the line to the left should maybe be more like... starting around his chin). Either that or he looks like he has his head retracted as far back as he can handle, which is pretty awkward.
His leg that's covered... the shape of the pants implies he has very thin hips... Like, maybe around the width of his head or smaller. Even if he is skinny, his hips should be wider than his head.
His shoulders also look awkward, though I can't really explain how.
Lastly, he's kinda staring off into space rather than looking the girl back in the eyes... which I think is weird.

The girl looks pretty good overall. I'd personally give her wider hips, but I don't think it's a problem as is.