A former employee of Kenzo Tange was Arata Isozaki who was initially interested in the Metabolist Movement and produced innovative theoretical projects for the City in the Air (1961) and Future City (1962). However he soon moved away from this towards a more Mannerist approach similar to the work of James Stirling. This was particularly striking at the Oita Branch for Fukuoka Mutual (1967) with its mathematical grids, concrete construction and exposed services. In the Gunma Prefectural Museum (1971–74) he experimented with cubic elements (some of them twelve metres to a side) overlaid by a secondary grid expressed by the external wall panels and fenestration. This rhythm of panelling may have been influenced by Corbusier's detailing on the Museum of Western Art in Tōkyō.