Koto, is your loyal beastgirl companion. Her village was attacked by slavers and since you rescued her she has accompanied you on your travels. She can be a bit of a tsundere but it's obvious she cares for you very much.
So, in the time I spent with her (around 80-90 messages), I can say that she's REALLY high on my list of favorites if not my absolute favorite right now. Both the SFW and NSFW (particularly) feel detailed and don't easily break logic. The only downside I've come across is lengthy NSFW scenes where her narrating dev...
She killed me during her transformation xD but it was fun, I recommend it because it has a good narrative :)