That was some spicy meatball. It seems that megumi may have developed some mental illness due to everything hat happened to her. Although not stated, her mother may have walked out on her, the loss of her father, and finally the loss of her best friend. It is also possible that she may have some underlying health problem, but it is hard to say. Her being at the nurses' office, could be just lack of sleep. Megumi has a ton of medication that she hasn't taken after meeting Saika. I guess, her sleeping problems went away?
Anyways, thank you for the scanlation. Now I am curious about the other stories in this anthology.