was a Japanese samurai 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...

, a member of the Miyoshi clan

Miyoshi clan

The Miyoshi clan is a Japanese family descended from Emperor Seiwa and the Minamoto clan . They were a cadet branch of the Ogasawara clan and the Takeda clan....

 who served as daimyo

Daimyo

is a generic term referring to the powerful territorial lords in pre-modern Japan who ruled most of the country from their vast, hereditary land holdings...

 of Awa

Awa Province

Awa Province may refer to:* Awa Province in modern-day Chiba Prefecture* Awa Province in modern-day Tokushima Prefecture...

. He is remembered as the cousin of Miyoshi Chōkei

Miyoshi Chokei

, eldest son of Miyoshi Motonaga, was a Japanese samurai and daimyo who was lord of the Miyoshi clan during the Sengoku period. Nagayoshi held the court titles of Shūri-dayū and Chikuzen no Kami , and was also known by the more Sinic reading of his name: Chōkei...

. Masanaga had very strong relations with the Ikeda clan

Ikeda clan

The was a Japanese clan that claimed descent from the Seiwa Genji. In the Edo period, several of the clan's branches were daimyo families, most notably of the Tottori Domain, and Okayama Domain. Takamasa Ikeda, present head of the Okayama Ikeda house is a husband of Atsuko Ikeda, fourth daughter...

, as Ikeda Nagamasa

Ikeda Nagamasa

Ikeda Nagamasa was a kokujin and samurai commander in the Sengoku period.Ikeda Katsumasa and Ikeda Tomomasa were his sons.His father was Ikeda Nobumasa and his mother was Miyoshi Masanaga's daughter....

was his son-in-law. Due to this strong relation between the families, Chokei considered him a threat. After 1548, Masanaga engaged in a major battle against his cousin, which ended in Chokei's victory. Masanaga's whereabouts after this battle are unknown.