Due to her drunken father's negligence, their mother passed away. Afterward, older sister Sumire was forced into an extreme existence—caring for her bedridden father and younger sister Shiori, while supporting the family by sucking the landlord's cock. Wanting to relieve her sister's suffering, adult Shiori also begins selling her pussy to seniors to survive. For these sisters, selling their bodies was the only way to make money and stay alive. When Shiori is touched by the landlord's huge cock, she convulses from overwhelming pleasure. Meanwhile, Shiori's boyfriend and sister Sumire engage in a purely lust-driven affair.