Former Prime Minister's Official Residence (now PM's Residential Quarters)

The Former Prime Minister's Official Residence (旧内閣総理大臣官邸), now known as the Prime Minister's Residential Quarters (内閣総理大臣公邸, Kōtei), stands in Nagatacho 2-chōme, Chiyoda Ward, Tokyo. Completed on March 18, 1929 (Shōwa 4), it was designed by Shimomoto Muraji (下元連) of the Ministry of Finance's Building Division (大蔵省営繕管財局). The two-story reinforced concrete building with brick cladding adopted an Art Deco and Expressionist architectural style heavily influenced by Frank Lloyd Wright's Imperial Hotel (1923), featuring geometric ornamentation, grand reception halls, and stately interiors befitting the seat of executive power.

The first prime minister to use the building was Tanaka Giichi (1927–1929). Over the following decades, the residence became the stage for some of the most pivotal events in modern Japanese history.

On May 15, 1932, young naval officers stormed the residence during the May 15 Incident (五一五事件), assassinating Prime Minister Inukai Tsuyoshi in his office. Bullet scars from this attack remain visible in the entrance hall to this day, preserved as silent witnesses to the violence of the era.

On February 26, 1936, during the February 26 Incident (二・二六事件), approximately 1,400 rebel soldiers of the Imperial Japanese Army occupied central Tokyo. A contingent attacked the Prime Minister's Official Residence, seeking to assassinate Prime Minister Okada Keisuke. In the ensuing chaos, the rebels mistakenly killed Okada's brother-in-law, Colonel Matsuo Denzō, believing him to be the prime minister. Okada himself narrowly escaped by hiding in a storage closet for two days before being smuggled out disguised as a mourner at his own funeral. The residence sustained significant damage from gunfire during the assault.

During the Pacific War, the building served as the primary venue for cabinet meetings (閣議) that shaped Japan's wartime policies. Prime Minister Tojo Hideki (October 1941 – July 1944) presided over war cabinet sessions here, including the decisions that led to the attack on Pearl Harbor and the conduct of the war across the Pacific. The adjacent wooden annex known as "Nihon-ya" (日本家, "The Japanese House"), built in 1937 as a traditional-style reception space, was destroyed in the devastating Tokyo air raids of May 1945, though the main concrete building survived with damage.

In the war's final months, Prime Minister Suzuki Kantarō (April – August 1945) used the residence as the center of Japan's agonizing deliberations over surrender. Following the atomic bombings of Hiroshima (August 6) and Nagasaki (August 9) and the Soviet declaration of war, the Supreme War Council and cabinet met repeatedly at the residence. On August 14, 1945, the final cabinet meeting was held, culminating in Emperor Hirohito's sacred decision (聖断) to accept the Potsdam Declaration and end the war. In the early morning of August 15, just hours before the Emperor's surrender broadcast, ultranationalist rebels attacked the residence in connection with the Kyūjō Incident (宮城事件), though Suzuki had already evacuated.

After the war, the building continued to serve as both the prime minister's workplace and residence through the postwar era. By 2000, after more than seven decades of use, the government decided to construct a new, modern Kantei immediately to the north. The new five-story Kantei opened in April 2002. Rather than demolishing the historic 1929 structure, the government undertook a remarkable hikiya (曳家) operation from October to November 2003, rotating the approximately 20,000-ton building 8 degrees east while moving it roughly 50 meters south. The building was then meticulously restored to its original 1929 appearance and reopened in 2005 as the Kōtei (公邸) — the prime minister's residential quarters, separate from the workplace.

The Kōtei is famously reputed to be haunted by the ghosts of those who died violently within its walls, particularly the victims of the May 15 and February 26 incidents. This reputation has reportedly made several postwar prime ministers reluctant to reside there, with many choosing to commute from their private homes instead.