>>2703039Ayana Taketatsu is known to be an imouto lover. She's basically 3d Kirino and was perfectly cast for the character. She actually went on twitter and was extremely happy when the LN ended since she didn't have to hold anything back anymore (She knew the script way beforehand) and wanted to share the ending with everyone.
https://www.youtube.com/watch?v=a4z4O_NGHlIYuichi Nakamura, on the other hand, actually doesn't care too much for imouto characters or even siblings. It's well known that he personally would have gone for Kuroneko or Ayase. There's interviews out there including the animated commentary for S1 where he talks about that.