Also bought this the moment it came out for Sakusei Byoutou, but thought to wait it out before posting. Glad someone beat me to it. Also if you're all curious the nurse is Numajiri, aka one of the main antagonists of the entire series. And a TLDR of the story (from what I can read): Her fixation with Yamada started with the original patient before him, where her harmless bullying became worse and worse (to the point of raping him) and now it's got to the point where she never wants to let Yamada go as she did with said patient. She torments/rapes him in the chapter, drags Mochizuki and a totally normal store clerk in her vile torture, and threatens to enslave/take Yamada with her to her apartment as her pet after his treatment is done. The manga chapter ends with her saying that she looks forward to when Yamada-kun is discharged, and saying that she has a collar ready for him (for when she takes him back to her apartment as her slave).
And if you're all curious, based on how I have been observing it, the manga adaptation is close to being half-way done.