The Iwakubo-yakata was a short-lived yakata (fortified manor hall), and the residence of Kawajiri Hidetaka, a vassal of Oda Nobunaga. The yakata was established when Oda forces conquered Kai in 1582 and wiped out the Takeda Clan. However, later that year Oda Nobunaga would be betrayed by Akechi Mitsuhide and compelled to commit suicide at Honnōji. With the death of Oda Nobunaga, then de facto ruler of Japan, a huge power vacuum opened up and the nascent regime in Kai collapsed. This led to mass rebellion in the province, and former vassals of the Takeda Clan rose up and attacked their new rulers. Indeed, after only two months of Kawajiri rule from Iwakubo, Kai had not been pacified, and many former Takeda vassals rallied to the side of Tokugawa Ieyasu. Mitsui Yaichirō besieged Iwakub-yakata, and Kawajiri Hidetaka fell on his sword. Hōjō Ujimasa and Tokugawa Ieyasu then invaded Kai.
Although no ruins remain, the site of Iwakubo-yakata can be found by searching for the Kawajiri Mound south of the cenotaph for Takeda Shingen. From the Shingen mausoleum one has to enter into the grounds of an old school, cross a gateball court, and then slip through a small door in a chain-link fence, following a narrow, hidden path behind several homes. Here there is a small stele commemorating Kawajiri Hidetaka and his short-lived rule over Kai Province. This hidden piece of history, overshadowed by a monument to the great Shingen, seems treated like a secret best forgotten.
|English Name||Iwakubo Yakata|
|Castle Type||Fortified Manor|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Access||Kōfu Station on the Chūō Line; 35 minute walk|
|Visitor Information||24/7, free|
|Time Required||10 minutes|
|Location||Kōfu, Yamanashi Prefecture|
|Coordinates||35° 40' 50.95" N, 138° 34' 59.81" E|
|Added to Jcastle||2023|
|Admin Year Visited||Viewer Contributed|
|Friends of JCastle|