Ono Michiyoshi served as a bushō during the Sengoku period.  He was a chief retainer of the Ii family and a kokujin, or provincial landowner, in Iinoya in the Inasa District of Tōtōmi Province.  He was also known as Ono Masatsugu.

Michiyoshi was born as the lineal heir of Ono Masanao who served as the chief retainer of Ii Naomori who governed Iinoya in Tōtōmi.  In 1554, after the death from illness of Masanao, Michiyoshi inherited the headship of the clan.  Prior to his demise, Masanao did not get along well with Ii Naomitsu (Naomori’s uncle) and threatened to murder him, posing a danger to the Ii family.  After the death of Masanao, Ii Naochika (Naomitsu’s son) returned to Iinoya from exile in Shinano Province and became the adopted heir of Naomori.

In the fifth month of 1560, members of the Ii participated in a westward march by their lords, the Imagawa clan, but the Imagawa army suffered a major loss to Oda Nobunaga at the Battle of Okehazama.  Ii Naomori died in the conflict but earlier, out of concern that the Ono family would act with impunity again, he left a will for Nakano Naoyoshi (from a cadet family of the Ii) to serve as a guardian for his adopted heir, Naochika.  Naomori’s grandfather, Ii Naohira, fulfilled these wishes and served as the guardian of Naochika.  Within the Ono family, Ono Tomonao (Michiyoshi’s younger brother) and Ono Gengo (a family member) were killed in action.  In the twelfth month, Michiyoshi assassinated Okuyama Tomotoshi, the father-in-law of Tomonao and a relative of the Ii family.

In neighboring Mikawa Province, Tokugawa Ieyasu abandoned the Imagawa in lieu of an alliance with the Oda clan following their victory over the Imagawa at the Battle of Okehazama.  Around this time, Naochika also leaned in favor of the Tokugawa family and secretly colluded with them.  Owing in part to the conflict between their fathers (Ono Masanao and Ii Naomitsu, respectively), Michiyoshi and Naochika had poor relations.  Michiyoshi plotted to seize Iinoya but because Nakano Naoyoshi served as guardian for Naochika, he could not achieve his goal.  Having learned of Naochika’s collusion with the Tokugawa and Oda, in 1562, Michiyoshi brought a claim to Imagawa Ujizane of Sunpu, alleging that Naochika was colluding with the enemy and planning to rebel against the Imagawa. 

After Ujizane attempted to raise an army to pursue Naochika, Naochika headed toward Sunpu to apologize to Ujizane but, on the way along the Kake River, he was murdered by a retainer of the Imagawa named Asahina Yasutomo.  Upon orders from Ujizane, Michiyoshi tried to kill Naochika’s orphan, Toramatsu (later known as Ii Naomasa), but was blocked by Niino Chikanori, a senior retainer of the Imagawa close to the Ii family.  Thereafter, in 1563, Ii Naohira died and, in 1564, Nakano Naoyoshi was killed in battle.  Prior to his demise, Naoyoshi had been overseeing Iinoya from Iinoya Castle, so Jirō-Hōshi (Ii Naotora), the daughter of Ii Naomori, became the next lord of the castle.

In 1568, Takeda Shingen of Kai Province invaded Suruga Province, the home province of the Imagawa clan.  Michiyoshi then joined the Imagawa army in Sunpu.  He was ordered by Ujizane to murder Toramatsu, seize control of Iinoya, and then lead forces in support of the Imagawa.  Following orders, Michiyoshi entered Iinoya and seized the territory from the Ii family.  Toramatsu, along with Jirō-Hōshi, and Yūchinni (Naomori’s widow), sought refuge in the Ryōtan Temple (the family temple of the Ii clan).  Tokugawa Ieyasu responded to Michiyoshi’s tyranny by dispatching the Iinoya Group of Three (Kondō Yasumochi, Suzuki Shigetoki, and Suganuma Tadahisa) to recapture Iinoya.  Michiyoshi was defeated, withdrew from Iinoya, and went underground outside of Iinoya.  In 1569, when Ieyasu attacked Horikawa Castle, he was found.  On 4/7, he was publicly executed at Ganibuchi, a location for the imposition of punishments by the Ii family along the Iinoya River to the east of Iinoya Castle.  On 5/7, Michiyoshi’s two children were also executed.  Near Ganibuchi, there is a cluster of stone pagodas built by local residents to pray for the repose of their souls.

Diety of Tajima

In a story about the Nakai family written in the early Edo period, after Tajima-no-kami (Michiyoshi) was sentenced by the Ii family to commit seppuku, following his death, he turned into an evil spirit and cursed the descendants of Nakai Yosozaemon so they enshrined him and received a divine message to call him the Diety of Tajima.  The Diety of Tajima remains enshrined to the present at the Ninomiya Shrine in Iinoya.