Obata Nobusada served as a bushō during the Sengoku period.

Nobusada was born as the son of Obata Norishige of the Kōzuke-Obata clan.  Either Nobusada or his father was also known as Shigesada.  Nobusada’s son may have also been named Nobusada as written with a different character, but it is not certain.  Nobusada was the lord of Kunimine Castle in Kōzuke Province.  According to one military chronicle, Nobusada and his father were in charge of 500 soldiers, the largest battalion in the Takeda family.

The Obata were originally kokujin, or provincial landowners, in Kōzuke.  On a par with the Nagano clan in terms of influence, the Obata supported Uesugi Norimasa as the deputy shōgun of the Kantō.  Later, the clan came into conflict with Norimasa, separated from the Uesugi, and served Takeda Harunobu (Shingen).   After the advance by the Gohōjō clan into Kōzuke, the Obata maintained relations with both the Takeda and the Gohōjō.  In 1553, Norishige took his son to serve Harunobu at Shioda Castle in Shinano Province.  Before long, his son attended his coming-of-age ceremony, received the character “nobu” and adopted the name of Nobusada.

Nobusada and his father served the Takeda.  Beginning with attacks in Kōzuke, Nobusada served valorously in major battles including the Battle of Mimasetōge and the Battle of Mikatagahara.

The Obata clan affiliated with Nobusada was a different lineage than the Kōshū-Obata of Obata Toramori, Obata Masamori, and Obata Kagenori.  Upon orders of Shingen, the Kōshū-Obata changed their surname to simply Obata.

In 1575, Nobusada’s father was killed at the Battle of Nagashino, after which he inherited the headship of the clan (although there are differing theories).  According to one war chronicle, consideration was given to having the Obata replace Kiso Yoshimasa who could not be trusted and was located on the provincial border with the Oda.  Without regard to the authenticity of this source, Nobusada appeared to have received treatment commensurate with a hereditary retainer of the clan.

In the third month of 1582, the Takeda clan was extinguished by the Oda during the Conquest of Kōshū.  Based on the advice of a chief retainer named Morihei Saku-no-jō, Nobusada surrendered to the Oda army.  Nobusada was then engaged as a yoriki, or security officer, of Takigawa Kazumasu.  In the sixth month of 1582, Nobunaga died unexpectedly in a coup d’état known as the Honnō Temple Incident.  Thereafter, Hōjō Ujinao defeated Kazumasu at the Battle of Kannagawa en route to expelling the Oda clan from Kōzuke so Nobusada surrendered to Ujinao and became a retainer of the Hōjō clan.  He did not have a natural son.  In 1585, he transferred the headship of the clan to his adopted heir (the son of Nobusada’s younger brother) and retired.

In 1590, during the Conquest of Odawara, Nobusada holed-up in Odawara Castle.  After the defeat of the Hōjō clan, Nobusada turned for support to the Sanada clan with whom he had close relations from the era when Sanada Yukitsuna was a wandering samurai and continuing throughout the time that Nobusada served the Takeda.  At the time, Sanada Masayuki was the head of the Sanada during the era of Katsuyori and in charge of offensives in the direction of Kōzuke.  Nobusada spent the rest of his life with them, dying in 1592 at the age of fifty-two.

According to one theory, Nobusada’s father, Norishige, died during the Daiei era (1521 to 1528), and the achievements attributed to Norishige were actually those of Nobusada.  Nobusada was known as a fearless bushō and leader of the Red Corps.  The authenticated biography of Oda Nobunaga known as the Shinchō-kōki contains a paragraph regarding the Battle of Nagashino that refers to the Obata forces as a talented cavalry.  His younger brother died in this battle.

Anecdotes

After Shingen decimated the Nagano clan, he told Nobusada that he would like him to separate from his wife and form a new connection with a family serving as hereditary retainers of the Takeda.  Nobusada responded: “If this was before the fall of the Nagano, I would accept it.  I distanced myself from my lord, Uesugi Norimasa, am hated by Terutora of Echigo, and was rescued by the Takeda family just before being killed in the course of their family disputes.  I cannot return the deep indebtedness that I have toward you.  However, as of now, my wife’s family has been eliminated and she has nowhere to go.  Therefore, even if I am ordered to be executed, I cannot leave her at this time.”  Deeply impressed by Nobusada’s words, Shingen responded “With your splendid willpower, I will have you serve in the vanguard in the next battle.”  Shingen also had his nephew, Takeda Nobutoyo, wed Nobusada’s daughter, becoming Nobusada’s son-in-law.