The site is located at the foot of Mt. Rokko, near the former Yamamura residence (by F.L.Wright), and it is blessed by the green scenery of the mountain. 

The little heavy traffic of the road bordering the lot, which is also a sightseeing route, was the first problem to face during the design phase. Moreover, the control of the size of the house in the small budget and the neighboring houses became another central theme during the initial study phases.

The result is a small house that strongly relates to geometrical composition and expresses well the relationship between the inside-outside space as the relationship between the family.

Two squares make a constriction in a one-room space. The first floor is divided to make different recesses in the house. On the second floor, a cross-wall divides the square. A spiral staircase is placed in the core center of the house to connect the three spaces. 

Maintaining the spatial purity, we carefully considered the layout and dimensions of each architectural element to lead the ambiguous relationship between inside and outside spaces, and also between the families.

The outer walls of the living room are set in what in Japanese is called "windmill style ". The walls and windows have rotational symmetry from the room's center,

The opening was set at a certain height to block the view from the neighbors to ensure privacy. Moreover, the set of windows contribute to keeping spatial continuities to the whole periphery of the site. it is possible to see the green directly or through the room.

While the surrounding wall ensures a sense of safeness to the house, the role of the windows is to open it to the outside in all directions.

On the 2nd floor, an opening was set in the center of the outer wall so that the two areas share one window. The width between this window and the cross wall was reduced to 550 mm to create spaces that provide proper distance between children.

This unique spiral staircase (the center of the stair is a straight line) is useful to make minimal area for the stairs and corridor. Its size is the smallest in the plan. By the reason the thickness of the slab is minimum, the space under the stairs can use as a corridor.

This spiral staircase serves as a partition between the entrance and the bedroom.

The curved surface of this concrete spiral staircase gives softness to rigid space. This sculptural geometric form goes beyond the function and becomes the Yorishiro (object in which a spirit draw), which symbolizes the unity of the family.