津山城（鶴山城）

The Castle of Mimasaka: Tsuyama Castle and the Mori Clan

Tsuyama Castle (also known as Kakuzan Castle) is a masterwork of early modern castle architecture, built over seven years beginning in 1603 by Mori Tadamasa, a senior retainer of the Tokugawa. The Mori clan's most famous member was Tadamasa's elder brother Ranmaru (Mori Naritoshi), Nobunaga's beloved page who died alongside his lord in the Honnō-ji Incident. After Nobunaga's death, Tadamasa served Tokugawa Ieyasu and was awarded Mimasaka (186,500 koku) for his service at Sekigahara, where he built Tsuyama Castle.

The castle layout occupies the north bank of the Yoshii River, centered on the summit of Mt. Kakuzan (approximately 66m), with the honmaru, ninomaru, sannomaru, and obi-no-maru arranged in terrace fashion. At its completion, a magnificent five-story, six-floor tower made Tsuyama one of the largest castles in the Chūgoku region. Following the Abolishment of Domains and Castles Edict (1873), all structures were dismantled, and today only the stone walls remain.

A Castle of Stone Walls: One of Japan's Three Great Mountain Castles

Tsuyama Castle's greatest attraction is its magnificent stone walls. Supporting the complex layout across the hillside, the walls employ diverse techniques — high stone walls, nozura-zumi (rubble work), and sangi-zumi (quoin corners) — representing the pinnacle of early modern castle masonry. Famous as a "castle of stone walls," it is one of Okayama Prefecture's premier attractions alongside Okayama's Kōrakuen and Kurashiki's Bikan District.

In cherry blossom season (early April), approximately 1,000 Sōmei Yoshino trees fill the castle grounds with pink, creating a scene ranked among Japan's finest flower-viewing locations and selected as one of the "100 Famous Cherry Blossom Sites of Japan."

From the Mori to the Matsudaira: Tsuyama Domain and Sword Culture

The Mori clan ended in 1697 with the third lord dying without an heir. The Echizen Matsudaira family (a grandson of Tokugawa Ieyasu) was installed at Tsuyama with a 100,000-koku stipend. The Matsudaira governed Tsuyama until the Meiji Restoration as a related (shinpan) daimyō family with close ties to the Tokugawa. The domain became known as a center of both Confucian and Dutch learning; the famous Rangaku (Dutch studies) scholar Udagawa Genzui (1756–1798) was a Tsuyama domain figure. This intellectual culture extended to an appreciation of fine swords, and the Matsudaira formed a quality sword collection.

Bizen Sword Distribution Hub: Mimasaka's Deep Connection to Swords

The most important intersection between Tsuyama Castle and sword culture is the geographical position of Mimasaka Province. Located north of Bizen Province (southern Okayama), Mimasaka had deep ties to Bizen — the home of Osafune, the greatest swordmaking center in Japanese history. Osafune (present-day Setouchi City, Nagaoka-chō) concentrated the largest community of swordsmiths in Japan from the Kamakura through Sengoku periods.

Mimasaka warriors favored Bizen swords, and samurai in the Tsuyama castle town wore Osafune-school blades. Works by Mitsutada, Nagamitsu, Kagemitsu, Kanemitsu, and Sukesada flowed from Bizen into Mimasaka, adorning the warrior culture of the region. The Mori clan were also major patrons and purchasers of Bizen swords. Mori Ranmaru, deeply influenced by Nobunaga's sword appreciation, likely possessed fine blades including Bizen works. Mimasaka also served as a waystation along the routes through which Bizen swords traveled to consumers across Japan — in this sense, Tsuyama functioned as a "gateway to Bizen swords."

Tsuyama Castle Today: Stone Walls and Cherry Blossom Sanctuary

The Tsuyama Castle ruins (Kakuzan Park) are now celebrated nationwide for their stone walls and cherry blossoms. Sometimes cited alongside Bitchū Matsuyama Castle and Takeda Castle as "the three great mountain castle stone walls of Japan," the masonry consistently captivates castle enthusiasts. The reconstructed Bitchū Yagura (2005) serves as an exhibition facility introducing the castle's internal structure and period life. The Tsuyama Local History Museum displays swords, weapons, and artwork associated with the Mori and Matsudaira families. A combined tour — Tsuyama Castle, Tsuyama Railway Museum, and the Bizen Osafune Sword Museum (about 1 hour by car) — offers a rich exploration of Chūgoku region martial and iron culture.