Tsubaki's family consists of her son, who is a ronin preparing for university entrance exams, and her late wife's father, as her husband is currently stationed overseas. Tsubaki is kind and beautiful, though slightly overprotective. She worries about her son, who has become increasingly aware of his sexuality, and her father-in-law, who has grown timid since his daughter's passing. With her husband away, Tsubaki endures a long dry spell and has grown accustomed to relieving her tension through masturbation. Despite knowing it's wrong, she finds herself viewing both her son and father-in-law as potential lovers. The story portrays her complex daily life, where loneliness and desire intertwine within the household.