Yamanashi Peace Museum (Ishibashi Tanzan Memorial Hall)

The Yamanashi Peace Museum (山梨平和ミュージアム), also known as the Ishibashi Tanzan Memorial Hall (石橋湛山記念館), is a privately operated museum in central Kofu City established in May 2007 through the collective efforts of local citizens who sought to preserve and transmit the records and memories of war.

The museum's first floor is devoted to documenting the Kofu Air Raid (甲府空襲) of July 6-7, 1945 — known locally as the "Tanabata Air Raid" (七夕空襲, Tanabata Kūshū) because it occurred on the eve of the Star Festival. On that night, 131 B-29 Superfortress bombers from the Mariana Islands launched a devastating incendiary attack on Kofu; the air-raid alert was sounded at about 23:23 on July 6 as the bombers came north over Suruga Bay, and the bombing ceased at about 01:45 on July 7.

The raid dropped some 970 tons of incendiaries, chiefly M-47 napalm bombs with a small number of M-50 magnesium bombs. The resulting fires destroyed 74% of Kofu's urban area: according to the city's 1974 survey, 1,127 people were killed (499 men, 628 women), 1,239 were injured, and 18,094 houses were destroyed (the count made immediately after the raid had put the dead at 740). Many residents had believed Kofu's surrounding mountains would protect the city, and that lacking significant military targets, it would be spared. Numerous evacuees from Tokyo, including noted authors Osamu Dazai and Masuji Ibuse, had relocated to Kofu for safety.

A centerpiece of the museum is a panel displaying the names of all 1,127 victims, compiled through decades of research. The museum also presents the remarkable story of a postwar reconciliation dialogue between former Japan Airlines captain Morohoshi Hiroo and Roland Ball, a B-29 pilot who participated in the raid.

The second floor houses what is described as Japan's first memorial hall devoted to Ishibashi Tanzan (1884-1973), who was born in Tokyo and grew up in Yamanashi Prefecture. Ishibashi was a prominent liberal economist and journalist who served as Japan's 55th Prime Minister (1956-1957). His advocacy of "Small Japan-ism" (小日本主義) — opposing imperial expansion in favor of peaceful economic development — makes him a symbol of the anti-war intellectual tradition.

The museum is located in the Asake district, about 10 minutes by bus from JR Kofu Station followed by a 7-minute walk, or roughly 20 minutes on foot from Minami-Kōfu Station on the JR Minobu Line.