Armadillo is located in Kamakura, Japan. With the sea to one side and the other 3 surrounded by mountains, this town’s topography provides ideal protection from enemy. This feature led Kamakura to become the political center of Japan in the 12th century. The clients- a couple and her father - bought the site with its old house four years ago. The clients collect furniture and musical instruments from all over the world, so the existing house is currently full of their collection. Now they have requested a low-cost annex space from us. It's for playing music, relaxing, sleeping well and hosting parties at home in their garden, similar to a weekend house. This location is defined by the existing house, a persimmon tree and the property line delineated by a retaining wall. The diamond shape is produced by these site elements. The first floor opens to the surrounding green landscape; the second floor closes like a lair. The restroom is positioned on the north side of the house and separated from the other spaces. This structure is constructed by many regular triangles, and the second floor is constructed by some surfaces. It's like a monocoque. Why do we call this house an armadillo? We needed something that could capture the interesting things that we shared with the clients and the intention that we would move creatively towards a house together. The animal reads sunlight and wind, an environment such as ups and downs of the land. And once this information is processed, then they choose a comfortable bed. This animal behavior fits well with the concept of this house and the environment of the site. ＊The word armadillo means "little armored one" in Spanish. They sleep in a lair for 18 hours every day.