The Takasugi household, a poor single-mother family, finally achieved stability when Mari's mother, Kyoko, remarried a corporate elite named Yoshio. However, Yoshio, who initially appeared to be a kind father figure, gradually revealed his true nature and began coercing and threatening his stepdaughter Mari. Burdened by her mother's struggles and her younger brother's illness, Mari silently endures the abuse to preserve her family's fragile happiness. Day after day, she suppresses unwanted orgasms—beside her mother, near her brother, even while on dates with her boyfriend. This story portrays just how heavy, yet heartbreakingly precious, her suffering truly is.