Japan is a leading country with strong environmental protection policy. The Government promises zero carbon emission by 2050. To achieve this, many companies and sectors are encouraged to step up their effort to use environment-friendly materials including construction. One of such promising materials is a volcanic rock that is found in abundance in Japan. And the country is volcanically active land. Even its natural symbol, Mount Fuji, is actually a volcano. This company in Tokyo is promoting the use of volcanic rock to cover surface of building walls, bridges and roadside. The idea aimed at the beginning to make cosmetic effect to make building blending more in the surrounding natural scenery, but later moss and plant were growing out of the porous surface of the volcanic rock. This unexpected development revealed the potentiality of volcanic rock for fostering vegetation. Natural volcanic rock can be used in different sizes and shapes, even cut into a thin board of concrete with embedded volcanic rock that can be attached to the exterior of an already existing surface. Another material, which does not contain concrete, is super-thin, ultra-lightweight material which can be cut to any size and attached even to a curved surface of different shapes. The environment-friendly feature of volcanic rock makes it suitable to revive the ecosystem of the urban areas when used as a construction material.