Dai-ichi Life Insurance Building (GHQ SCAP Headquarters)

The Dai-ichi Life Insurance Building (Dai-ichi Seimei-kan) stands in Yurakucho, Chiyoda Ward, Tokyo, facing the Imperial Palace across the Hibiya moat. Designed by Watanabe Jin and Matsumoto Yosaku as the insurer's head office, it was begun in April 1935 and completed on 3 November 1938. The steel-framed reinforced-concrete building has seven storeys above ground and four basement levels, and its west front toward the moat is defined by ten square columns.

During the war the Army's Eastern District Army headquarters occupied part of the building and anti-aircraft guns were mounted on the roof. Solidly built and almost undamaged by the air raids, it was requisitioned after the surrender and chosen by General Douglas MacArthur as the General Headquarters of the Supreme Commander for the Allied Powers (GHQ/SCAP). An occupation headquarters looking directly across the moat at the Emperor's residence carried obvious symbolic weight.

From 1945 MacArthur directed the occupation from his sixth-floor office until he was relieved in April 1951, and GHQ remained here until 1952 — nearly seven years in all. The drafting of Japan's postwar constitution, the dissolution of the zaibatsu, land reform and women's suffrage were all directed from this building. It was returned to Dai-ichi Life in July 1952.

The site was redeveloped from 1989 together with the neighbouring Norinchukin Bank building. The eastern part was demolished in December 1989 for a high-rise block; the western part was renovated from October 1993 and completed in September 1995 as the main building of DN Tower 21 (now Dai-ichi Life Hibiya First). The west facade was preserved, but the interiors were almost entirely rebuilt; only MacArthur's sixth-floor office survives as a memorial room. The room is not a freely accessible gallery and has been opened only on particular occasions, such as a reopening in July 2015, so visitors should check the company's current arrangements.