Hoteru shimai: Shiri Kansen aibu

Original title: 火照る姉妹 尻・感染愛撫

As Morimi Shizuka leisurely sips a hot drink at the front door, a masked office worker on his way to work coughs visibly as he passes by. Shizuka, a practicing doctor, lives with her father Shigeru (Iijima), a research doctor working at a university hospital, and her younger sister Mai, but there is no word on the whereabouts of the sisters' mother. Shigeru has been feeling unwell since the night before, and as she takes a morning bath, Mai blares out loud music with no thought for her father, leaving Shizuka speechless. Mai unilaterally tells her sister that she is bringing her boyfriend home that day, and although Shizuka is concerned about Shigeru, she goes to work. Morimi Clinic is run by Shizuka and nurse Hase Shu (Salmon). However, Shizuka does not at all betray the impression of being laid-back, and in fact, her mood accelerates.