Hana smiled, a sad, knowing expression. "It's been a while. You haven't changed."
appears to refer to characters from the multimedia project The Fruit: The Account of That Citrus (often translated as "Her Fruit").
: Her name literally means "citrus fruit" in Japanese, which is a common naming motif in romantic or "Yuri" drama series.
It is described as a Japanese graphic novel (manga) and animated (cartoon) series.
“Stop,” she said. Not loud. But the word was a period. The sentence ended.