A trivial dispute erupts into a marital fight, and Yuta's angry wife storms out. Her older sister Ruisa offers to mediate and gently comforts the bewildered husband. With her beautiful face, exquisite waist and perfectly balanced model figure pressed close, Yuta starts having inappropriate thoughts and escapes to the bath. But Ruisa barges straight in without giving him any choice, beginning a two-day stay in which she keeps getting him off.