Seo Dae Yeong and Kim Gi Bum: I like that in the beginning they made Gi Bum out to be some kind of rough around the edges 'gangster' kid, but then they show him crying and just in general acting a bit more childish since entering the army. Like, he had to grow up quickly (not to say he was mature but he was stealing, in a gang, etc.) and now he has the chance to live more like his age warrants. Though I suppose he still is rough around the edges ~
Dae Yeong because he seems like a good person but is perhaps a little emotionally stunted, so of course there will be a lot of character growth! It's interesting to see how he acts quite standoff-ish to even people he is close to, and to see how he acts based on what he thinks is right/wrong (how he chooses to do what he believes is the right thing even if it hurts him, and even how he chooses to do what he thinks is the right thing when it hurts other people, as long as he thinks it is the option that will hurt them least in the long run). And how he pretty much embodies the "cog in a machine" metaphor often used for soldiers; if he's told do something, he does it without verbal questioning. Like I said, I'm interested in how his character will grow.