Matsuyama Castle & Former IJA 22nd Infantry Regiment Site

Matsuyama Castle (松山城, Matsuyama-jō) rises atop Mount Katsuyama (132 meters) in central Matsuyama City, Ehime Prefecture. Originally constructed beginning in 1602 by Katō Yoshiaki, the castle is celebrated as one of Japan's twelve remaining original castle keeps. However, beyond its feudal heritage, the castle grounds played a pivotal role in Japan's modern military history as the headquarters area for the Imperial Japanese Army 22nd Infantry Regiment (歩兵第二十二連隊), one of the principal army garrisons of Shikoku.

The 22nd Infantry Regiment at Matsuyama (1884–1945)

The 22nd Infantry Regiment was established in 1884 (Meiji 17) at Matsuyama, under the Hiroshima Garrison, with its 1st Battalion initially stationed in the city. The regiment received its colors on 17 August 1886 and completed its full formation by December 1888. The regimental barracks were constructed on the Sannomaru (third bailey) of Matsuyama Castle, an area known as Horinouchi (堀之内), while the Ninomaru (second bailey) was converted into an Army Garrison Hospital (陸軍衛戍病院) in 1917 during barracks reconstruction.

From 1886 onward, both the Ninomaru and Sannomaru were placed under the jurisdiction of the Army Ministry, transforming the castle from a feudal stronghold into a modern military installation. The regiment recruited soldiers primarily from Ehime Prefecture and became one of the core units of the 11th Division when it was established at Zentsuji in 1898, with a recruitment area spanning all four Shikoku prefectures.

"The Iyo Flesh-Bullet Regiment" — Russo-Japanese War (1904–1905)

The 22nd Regiment earned its fearsome reputation during the Russo-Japanese War, particularly at the Siege of Port Arthur and the Battle of Mukden, where its soldiers displayed extraordinary tenacity. The regiment became known as the "Iyo Nikudan Rentai" (伊予の肉弾連隊, "Iyo Flesh-Bullet Regiment"), a name reflecting both the ferocity of its assaults and the heavy casualties sustained. This reputation made the regiment one of the most celebrated — and feared — infantry units in the Imperial Japanese Army.

Pacific War: From Manchuria to Okinawa (1939–1945)

In October 1939, with the reorganization of the 11th Division, the 22nd Regiment was transferred to the newly formed 24th Division, and its recruitment area shifted from Ehime to Hokkaido. The division was stationed in Manchuria (Tōan City, East Manchuria) for garrison and anti-Soviet duties. In August 1944, the 24th Division was redeployed from Manchuria to Okinawa to reinforce the island's defenses against the anticipated American invasion. The 22nd Regiment fought in the desperate Battle of Okinawa, and on 17 June 1945, the regimental commander and his remaining troops were annihilated (玉砕) — the regiment ceased to exist after 61 years of service.

Japan's First POW Camp (1904–1905)

Matsuyama holds the distinction of hosting Japan's first prisoner-of-war camp, established during the Russo-Japanese War. The camp was located at the 22nd Regiment's Jokuhoku Training Grounds, where 26 hospital buildings were constructed. Over 110 prisoner transport ships delivered approximately 6,000 Russian POWs to Matsuyama via Takahama Port, with peak numbers exceeding 4,000 at a time — in a city of only 30,000 residents.

The camp was established partly to demonstrate Japan's compliance with the newly ratified Hague Convention on the treatment of prisoners of war. Russian POWs were granted remarkable freedoms: they could visit the famous Dōgo Onsen hot springs, attend theater performances, and move relatively freely within the city. The humane treatment became legendary among Russian soldiers, with some reportedly shouting "Matsuyama!" upon surrendering, hoping to be sent to the well-regarded camp. Ninety-eight Russian prisoners who died in captivity (Colonel Vasily Boisman and 97 others) are buried at the Russian Soldiers' Cemetery (ロシア兵墓地) in Matsuyama, with their gravestones oriented northward toward their homeland.

Present Day

After Japan's surrender in August 1945, the military facilities on the castle grounds were dismantled. The Sannomaru area was converted into Shiroyama Park (城山公園) and sports facilities, including a baseball stadium. The castle itself was designated a National Historic Site in 1952. The main keep (天守), which had been destroyed by fire in 1784 and rebuilt in 1854, survived the war and remains one of only twelve original castle keeps in Japan. Today, the JGSDF Matsuyama Garrison (陸上自衛隊松山駐屯地) is located nearby but separate from the castle grounds, continuing the city's long military tradition. The Ninomaru site has been restored as a traditional Japanese garden (二之丸史跡庭園), opened in 1992.