Shiori has a college student son, Ohga. Her remarried partner, Hiroki, has a daughter in ○ grade named Uta. They were supposed to have a happy remarriage... However, for Uta, the existence of her stepmother Shiori is unbearable as it feels like she's lost her father. Driven by this twisted love, Uta forces Shiori to be raped, threatens her with a weapon, and even coerces her into incest with her son...
