Architecture, Building and Structure Design Oiso Hillside Residential Villa by Krista Watanabe Oiso Hillside is a residential villa located in Kanagawa Prefecture, Japan. The design follows the natural shape of the sloping site instead of leveling the ground for construction. Skipped floors, a two-story ceiling above a sunken conversation area and a three-level deck form a dynamic interior. Views of the surrounding hills and mountains can be enjoyed from the living spaces. A Japanese seismic-resistant method with a wooden rigid-frame structure allows wide open spaces. Wood is the main interior material, and a few antique pieces add accents.