User blog comment:B214/Question and Answers 4/@comment-26216310-20150403114307/@comment-26268422-20150405014712

Issei's Heavenly Dragon's Aura subjugates and mesmerises those around him and it is natural for the women he is living with to be drawn to him. Akeno also explains how the ompetition between the girls to be next after Issei declared his love for Rias, probably brought on Koneko going into season. It seems like it would be perfectly inline with both her Yokai heritage and her role as a rook and as a 15 year old high school girl.

She is still every bit as tough, only now some of the love she could only give to (mostly) Rias and the rest of ORC is directed at Issei. At her age it would be wierd if she weren't attracted to the only male devil in her daily life that shows an interest in girls. Perhaps it can be read differently, but I think Ishibumi did a great job making Koneko-chan into something other that just another LN Archetype.