Thanks for the scanlations :D
Holy crap; there's a serious plot? This manga just keeps getting better!
Also, the art and panelling was incredible this chapter. That was true for previous chapters as well, but the serious nature of this chapter really showed how good the author is at creating an atmosphere when they want to. The panel of Kaguhara upon entering her home was so oppressive... I love how the mangaka could easily create fine art if he wanted to, but they choose to do this instead; in a way, they're similar to Kaguhara.
Also, it seems like Kaguhara's notebook really is a pervert's Voynich manuscript, since Shitori can only see the drawings.
So many amazing references this chapter. Mikamo looked like she came out of Doraemon when explaining her stalking skills. Kaguhara became an irasutoya illlustration. Her seeing the "fetish thread" was clearly a Demon Slayer reference. I think that was an Ultraman face as well, but I'm not sure.
Doraemon
irasutoya
Demon Slayer
Ultraman (? Unsure)