Having loved reading since she was a child, Mio entered the literature department of a national university and once aimed to become a literature researcher. However, she is now married to the man she met at university and has one son. Although she loves her child, she is beginning to feel bored with her life as an ordinary housewife. At that time, her son decided to bring his friends over to hold a study group, and Mio was to be the instructor... However, as she interacted with her son's youthful friends, her sadistic side was stimulated...