Someone on another thread asked about the origins of Neko / Tachi. It's quite simple. People wanted to use words that sounded like Nico/Maki. Nico became a neko and Maki was a tachi. Everyone else in Tokyo went, "oh, that makes sense!"
^ Misaki (the blonde) and Kuroko (the one sitting on her lap) don't have the best relationship. For Misaki to actively embrace Kuroko and doing so happily is... concerning at best.
@Reirin: omg really? That's amazing, I'mma go and read them now!!