User blog comment:Ariel Saeba/Mythology and Character Origins in DxD/@comment-28087290-20160413071356

You know Koneko and Kuroka represent Yin and Yang.

Koneko's real name "Shirone" which means "White Sound" is a reference to Yang being white and sound being part of it. Her hair and tail colour also references Yang's colour. Her personality also relates because she is a bright and positive character and Yang means light and positivity is a part of it. Here are the others things that Yang represents that Koneko's character references: Energy, New Young, Strong, Good, Accept, Truth, Love, Open, Protect, Defence, Shield, Live and Life.

Kuroka is the opposite but of course we know the context of those opposites