This house was designed for a family of three in a residential area of Tokyo. The client requested windows that can open to a modest range to create the feeling of a comfortable, unconstrained space. Therefore, the selection of openings became a prominent theme for this 620-square-foot site surrounded by residential houses. Consequently, a plan was adopted to make maximum use of openings on the south facade and the roof for natural illumination, ventilation, and views, and constructed a structure without openings on the north, east, and west faces that are surrounded by a frontal road and adjacent houses. Along with this decision, the house was placed on the north side of the site in a shape-stretching east to west orientation. The second floor consists of one room stretching east to west with a full range of openings on the south face. The room can be divided freely with a sliding door that retreats into the wall. The living room on the first floor is located slightly higher than the ground level and has a veranda-like atmosphere. In the basement, the family can enjoy the entertainment of a home theater. A spiral staircase penetrating the center of these unique three layers gives a light sense of unity to the entire house.