Honestly, Stemwinder described whole Kiyoko ordeal on Fenexo forums better, at least to me, then anyone else did. Be they from here or there. I would recommend for everyone to read rest of his post in the thread since it presents pretty well articulated opinions on most of companions.
You must be registered to see the links
"Kiyoko:
+ Very involved content that links to and affects a large batch of other content - in fact she's probably got more by sheer volume than the next two runners-up put together. She combines a number of focal points for fans of these games (japanese-flavored stuff, breeding, marriage and child-rearing content) and pushes them far enough to satisfy most players who'd be drawn to her for those reasons. Unlike some of the other characters she has a mix of both likeable and unlikeable traits, too, so when stacked up against some of the flatter characters she stands out as someone her author put a lot of thought into bringing to life.
- There are both pluses and minuses to it so clearly being someone's pet character and story: the content itself is extremely self-contained and discordant with every part of the game that doesn't involve kitsune and -very- much on tracks, so those who might have liked to see how things play out differently (if their character didn't fall in love with Kiyoko, if their character were to approach it as more quid pro quo, if their character took offense to the way Kiyoko tries to freeze them out when it comes to parenting, if their character is female &c) might lose investment in it entirely if they don't perfectly agree with the direction it takes. There's so little player involvement past a certain point that many who were on board with it initially got fed up with it. Where Ryn's content found the line (between serving as an avenue to get you the player to feel more invested in the parts of the story that involve the character and getting so overwrought and self-indulgent in its 'look how complex and tragic and important my characters and all the content surrounding them are!' efforts that it feels desperate, as though it's trying to
force you to feel things through sheer volume) in giving the character a 'big' and involved backstory Kiyoko's shamelessly sails past it without so much as acknowledging it and then keeps going and going and going...and going. It even stops asking you whether you still care or not; you'll be bombarded with it regardless. This navel-gazing aspect of her content is probably the most polarizing in the game."