Metabolism is a kind of architecture that began in Japan around 1960. This way of designing buildings came out of the rebuilding of Japan after World War II. Members of the group include: Kiyoshi Awazu, Noboru Kawazoe, Kiyonori Kikutake, Kisho Kurokawa, Fumihiko Maki, Masato Otaka, and Kenzō Tange. They wrote a short book in English and Japanese called "The proposals for a New Urbanism" for the World Design Conference in 1960. Many Metabolist projects or designs were very large city plans called megastructures. The members thought of cities as living things that changed over long periods of time.
These architects were interested in building housing for large numbers of people. They often planned buildings that could be changed. One example is the Nakagin Capsule Tower by Kurokawa (1972). Each apartment was a rectangular block with one round window. These blocks could be added, moved, or removed as needed. It was a "plug-in building". Kurokawa planned for new, better capsules to be added to replace old ones. However, people living in the tower plan to tear it down and rebuild a larger building. 
- Solomon, Yuki (30 April 2007). "Kurokawa’s Capsule Tower To Be Razed". The Architectural Record. McGraw-Hill. http://archrecord.construction.com/news/daily/archives/070430kurokawa.asp. Retrieved 2011-12-03.