“A Small Castle Integrated with Nature.” The owner asked for “life in nature”. To realize “Urban Forest”, all the rooms are surrounded with various leveled green gardens and all the exterior spaces and surface of mass are integrated with greenery. We picked the dynamic group of Bukhan mountain summits as the object of relation-setting from the surrounding context. To maximize land use efficiency, according to building code, we designed polyhedral mass. Its inhomogeneous shape with the nearby Bukhan mountain peaks and the feature of white petals in folding paper represents its formative beauty.