Battle at Hashizugawa
Date: 6/28 of Tenbun 15 (1546)
Location: Near the Hashizu Bridge at the mouth of the Hashizu River
Outcome: The Amago prevailed following violent clashes by mounted soldiers on the bridge spanning the Hashizu River.
In the Battle at Hashizugawa (Hashizugawa no tatakai) in 1546, Amago Toyohisa of Aki Province opposed the combined forces of Takeda Kuninobu of Inaba Province and influential families (kokujinshū) from Hōki Province. This battle is viewed as a continuation of a broader confrontation between Yamana Hisamichi (formerly Nobumichi) of Inaba and his nephew, Yamana Suketoyo, of Tajima Province. This may also be referred to as the Battle at Hashizugawa.
During the Tenmon period (1532-55), Hisamichi and Suketoyo engaged in a struggle for control of the clan. The Amago clan supported Hisamichi while the Ōuchi clan joined with Suketoyo in an effort to surround Hisamichi. After Amago Haruhisa (formerly Akihisa) invaded Inaba in the summer of 1544, the Yamana of Tajima reconciled with the Amago and withdrew from Inaba.
In 1545, Suketoyo intensified attacks against Hisamichi, recruited Takeda Kuninobu away from Hisamichi, and reinforced Tottori Castle. In the fourth month of 1546, Hisamichi and Suketoyo achieved a rapprochement through the mediation of a kuge, or noble, named Yanagiwara Sukesada, but Suketoyo soon broke the peace. Later that year, Suketoyo determined that, in order to prevail in a final showdown, he must first end the support furnished by the Amago clan to Hisamichi. He then appointed Takeda Kuninobu as the general to lead an army with the kokujinshū of Hōki into Hōki.
Toward the end of the sixth month of 1546, Kuninobu and an army with 7,000 mounted soldiers marched into Hōki and attacked and captured Kawaguchi Castle, located on a hill overlooking the Sea of Japan. Kuninobu installed Kawaguchi Hisauji, former lord of the castle, and then led the army onward to Uma-no-yama in the Kawamura District. On 6/27, the army separated into two battalions alongside the Hashizu River at the base of the mountain. Kuninobu, together with Yukimatsu Masamori and Yamada Shigenao, commanded 5,000 soldiers at a crossing（渡り口）while Nanjō Sōshō and Komori Hisatsuna positioned 2,000 men at the mouth of the Hashizu River.
Across the river, Amago Kunihisa and Toyohisa led a contingent of 3,700 soldiers toward the crossing, while 2,000 mounted soldiers under the command of Yoshida Chikugo-no-kami set-up a position at the mouth of the river. At the crossing, the Takeda responded to a vicious assault by the Amago army with a flurry of arrows. Toyohisa and 700 horsemen cut their way into the opponent’s formation, but an arrow pierced his chest plate and he fell from his horse, after which he was promptly slayed by Nakahara Mokunojō, a follower of the Takeda. Upon hearing this news, Kunihisa rallied his troops to launch another fierce attack, overpowering the Takeda forces. Kuninobu fled with a small number of troops but killed himself after being caught near Uma-no-yama.
At the mouth of the Hashizu River, the armies confronted each other in the vicinity of the Hashizu Bridge. The battle occurred on the bridge, with the two sides engaged in a violent back-and-forth exchange. The rush of men coming to join the fight caused the bridge to collapse, with a deluge of men and horses alike plunging into the river below, causing many to drown. Nanjō Sōshō barely escaped after being rescued by a local fisherman.
While the Takeda waged battle against the Amago in Hōki, Suketoyo cornered Hisamichi in Inaba Province. Suketoyo succeeded in persuading Nakamura Masashige, a senior retainer of Hisamichi positioned at Shinyama Castle, to abandon Hisamichi and attacked Fusetenjinyama Castle in the Takakusa District of Inaba. Following the attack, Suketoyo lured Hisamichi to Tatsumi Ridge and, together with troops from Shinyama Castle, killed him in an ambush. Even though Suketoyo’s supporters lost in the Battle at Hashizugawa, Suketoyo was able to attack the Hisamichi allies in Inaba for half a year after slaying Hisamichi himself. Toward the end of 1546, the Yamana from Tajima controlled most of Inaba Province, and the new shugo originated from Tajima. Nevertheless, families based in the mountainous southern districts of Inaba including the Mōri, the Yabe, and the Kusakari remained firmly in opposition to the forces from Tajima. Suketoyo struggled in efforts to contend with them.