How people treat others can be highly influenced by how similar they are to the person they are interacting with. Because humans naturally form groups based on common interest, it enforces an "us versus them" mentality, that can be harmful toward outsiders. Yahari Ore No Seishun Love Come Wa Machigatteiru re-reminded me of this concept quite clearly during the camping trip arch. However, this idea does bleed throughout the whole series for both Hikigaya Hachiman and Yukinoshita Yukino.
The one thing that seems to stand out more for me, is the way Yukino explains her past, and how she acts now because of those events. During my first impression of the series, I got the vibe of Medaka Box, and I still would stick to the assessment. For me, Yukino and Medaka are stuck in similar situation, but choose to handle them very differently. And expanding on why is precisely why I'm writing this, but first, lets start with their similarities.
Similar
Both Yukino and Medaka seem to be the ones who are always perceived as "perfect", but they just have an easier time hiding their imperfections, if you don't look so closely. Hachiman realized this pretty late into series, and is now beating himself up mentally, because he ended up putting Yukino on a pedestal, and his image of her is slowly transitioning into something more realistic and human-like.
Since a lot of people have these misconceptions of them -- like Hachiman once had -- it became hard for them to fit in with everyone else. The talents they possessed, were a hindrance to any kind of social life they wanted to establish. And with that, they found their own way to deal with this problem, but both parties took the problem and followed very different paths.
But Different
Yukino's way of facing her problems, was to change herself completely -- at least from the way she presents herself -- and is most honest when it comes to people who criticize her. However, there are subtle clues that tell me she hasn't changed all too much, and is putting on a facade to make herself seem stronger than she really is.
On the other side, Medaka uses her talent as the solution to all of her problems. Because of her abnormality, it makes it easier for her to help others, and she goes out of her way to be useful to others. The only real downside to that is the fact that she puts others in front of herself, and she never knows what to do when she is in a time of need.
Loose Change
Of course, them being apart of the same coin, I feel that both will learn and grow from the people around them. Since Medaka Box and it's second season Medaka Box: Abnormal have ended, this prediction isn't much of a predict -- since it already concluded, and indeed Medaka has changed. But this is more toward Oregairu, it is very likely, we will see Yukino be more honest with herself, and might stop trying to shadow her sister to feel like she is changing herself. The keyword here is change, and lets just hope to see it in Yukino.