The space in a city like Tokyo is small, the apartments are too expensive so that the rationalization of space has become an obsession for Japanese architects. These apartments made by Sonoko Kambayashi is a good example. The main material is concrete, even in its interior walls and ceilings are concrete, with this whole facade material does not show monotonous, allowing the introduction to the design of the walls above the main entrance. Despite their appearance impermeable apartments, two floors enjoy abundant natural light, especially in the common rooms. Each apartment has about 65 square meters.