The project, an extended private space of the existing main housing and as a place to invite guests, is in Tokyo’s most esteemed hilly residential areas close to the downtown. The plan ensured conservation of the area’s irreplaceable natural assets, including abundant spring water and locally beloved large trees. A water garden has been utilized there.The building is connecting with the garden through water.Together with the light well, the large opening of 13m width, adjacent pool, water basins, and the sculptures with water flows, a refreshing and visually striking space are created.