Finally finished book 10 (parts 1 and 2) the other day. Just found this image right now. Translated. Nothing like this happens in the book though. Not sure why it was tagged with spoilers.
I guess back then it showed a new character. Not a real spoiler, but...
But Kuyou was introduced in book 9, which came out 4 years before this image was uploaded.
Updated
...Kuyou?She kinda looks like me...So she's basically like my kid!
No wonder she looks like me.She is a recombination of your genetic information and my genetic information.Now go out with me....Why are you doing this to me?The Surprise of Ryouko Asakura IVHey, Kuyou, who's that kid...?