Two high school sisters, Nonoka and Hinano, were living happily with their stepfather, Yoshiwo, in the countryside. However, one day, their stepfather passed away, and the one who took care of the two was their older brother, Koji, who had returned from the city. At first, Koji acted gently, but gradually the gaze he directed at the sisters became filled with desire, and he began a sinister domination. Nonoka desperately endured to protect her sister, and Hinano, while being crushed by fear, clung to her sister. However, Koji's abuse escalated, and eventually he brought a wealthy man into the house and forced the sisters to sell their bodies. In the dark house with no escape, the two try to survive while supporting each other, with a glimmer of hope in their hearts - Behind the sisters holding hands in front of the altar, Koji's shadow loomed, which would never disappear.