The idea of this ambiguous space is based on the common ground between interior design and art as a permanent installation. The project was launched as the second full-scale reconstruction project commemorating the 60th anniversary of Tokyo Tower; I have transformed the interior space of its circular observation deck, located at the height of 250 meters, with floor space of about 100㎡, into a “prismirrored space”, that is original idea by covering the whole space with polyhedron mirrors. The fundamental design concept is “a space created with the visitors and the scenery of TOKYO”.