If you're interested by the book the girl is reading: Edogawa Rampo's "The caterpillar" can apparently be found on Amazon, in the book named "Japanese Tales of Mystery and Imagination" by Edogawa Rampo, Patricia Bjaaland Welch.
Well this one was nice. I would've rather seen a more concrete conclusion like was that really a confession even? or something like that, but I feel like, compared to a lot of the yuris that have been coming out lately, something sweet and with a nice ending like this was LONG OVERDUE lol.