was the final head of the Shiba clan

Shiba clan

The was a Japanese clan claiming descent from the Minamoto clan of the Heian era that held influence and territory in the provinces of Echizen province and Owari province to which they were governors during the Sengoku era. However, they were unable to make a transition to Sengoku-daimyo and lost...

 and lived during the latter half of the Sengoku period

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

 of Feudal Japan. Nominally, Yoshimune was the governor of Owari province

Owari Province

was an old province of Japan that is now the western half of present day Aichi Prefecture, including much of modern Nagoya. Its abbreviation is Bishū .-History:The province was created in 646....

 and resided at Kiyosu castle

Kiyosu Castle

is a castle that acted as a base of operations for Oda Nobunaga during the latter half of the Sengoku period of feudal Japan. It is located in the city of Kiyosu, Aichi Prefecture, Japan....

. Though he was governor the head of the Iwakura Oda clan of Owari and the deputy governor of Yoshimune, Oda Nobutomo

Oda Nobutomo

was a Japanese warlord during the Sengoku period. He was head of the Iwakura Oda faction of the Oda clan, and ruled the four southern districts of Owari Province as shugodai...

, ruled behind him. Following the death of Oda Nobuhide

Oda Nobuhide

was a warlord and magistrate of lower Owari Province during the Sengoku period of Japan. His father was Oda Nobusada and Nobuhide was the father of Oda Nobunaga.-Ruling the clan:...

 in the year 1551 and Oda Nobunaga

Oda Nobunaga

was the initiator of the unification of Japan under the shogunate in the late 16th century, which ruled Japan until the Meiji Restoration in 1868. He was also a major daimyo during the Sengoku period of Japanese history. His opus was continued, completed and finalized by his successors Toyotomi...

's appointment to heir of his late father's position, Nobutomo, who was of the opposite family, planned to assassinate the heir. Yoshimune learned of these designs and reported them to Nobunaga, with whom he had a secret relationship. Nobutomo would then catch on to this hidden activity of Yoshimune and had him killed in turn. But Nobunaga was successful in hearing of the plan and assaulted Kiyosu castle, killing Nobutomo.