Building No. 21 (1914-1961) [From Sone to Yasuoka, and then to Sakurai Kotaro]

Marunouchi began with J. Condor's Building 1, then expanded to include Sone Tatsuzo's Buildings 4 through 7. Later, Yasuoka Katsuya designed Buildings 8 through 21, completing the streetscape of Babasaki-dori and Nakadori. This article outlines what Yasuoka inherited from Condor and Sone and how he passed it on to the later Sakurai Kotaro. Yasuoka designed Buildings 8 through 11 on the north side of Nakadori, maintaining the relationship between Sone's designs for Buildings 4 and 5 and Buildings 6 and 7 (simpler design for Nakadori compared to Babasaki-dori, with facade of the buildings facing each other aligned). On the south side, he designed Buildings 14 and 13, inheriting the Babasaki-dori design. Buildings 14 and 15, like those on the north side of Nakadori, are thought to have inherited Sone's design techniques. However, he went beyond simple inheritance and added another twist. One is the addition of a tower-like design toward the intersection where buildings 14, 15, 18, and 20 face each other. The other is that Yasuoka's final work, building 21, had a flat roof instead of the roof that buildings 20 had up to that point, making it a groundbreaking piece of architecture that attempted to transition from the British style to the American style of large-scale architecture. From then on, Sakurai developed architectural designs with flat roofs, and began to explore designs that could accommodate larger, deeper office buildings.