I like the premise of the game, I'm going to download it and see how it is.
There are a couple of tags that I don't like very much: humiliation and spanking. I always prefer to avoid those kinds of situations. In any case, since I don't like them, I always skip them, even if it's using the CTRL button.
On the other hand, to the question: What kind of personality would you like in your sister? I see that most have responded submissive and sundere (this I'm not sure what it means). I'm not a fan of domination at all, so I hope that if the relationship with her leads to male domination, there is another non-dominated path or that if the only possibility is male domination, establishing a romantic relationship with her can be avoided.