was a Japanese samurai

Samurai

is the term for the military nobility of pre-industrial Japan. According to translator William Scott Wilson: "In Chinese, the character 侍 was originally a verb meaning to wait upon or accompany a person in the upper ranks of society, and this is also true of the original term in Japanese, saburau...

 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...

, who most notably served the Oda clan

Oda clan

The was a family of Japanese daimyo who were to become an important political force in the unification of Japan in the mid-16th century. Though they had the climax of their fame under Oda Nobunaga and fell from the spotlight soon after, several branches of the family would continue on as daimyo...

. He was born in Mino Province

Mino Province

, one of the old provinces of Japan, encompassed part of modern-day Gifu Prefecture. It was sometimes called . Mino Province bordered Echizen, Hida, Ise, Mikawa, Ōmi, Owari, and Shinano Provinces....

, and first served the Saitō clan

Saito clan

The was a Japanese clan in Mino Province during the Sengoku period in the 16th century. According to records, the Saitō clan descended from the Fujiwara clan...

. After the fall of the Saitō, he was taken on as a retainer by 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...

. He was particularly active during the time of 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 entry into Kyoto

Kyoto

is a city in the central part of the island of Honshū, Japan. It has a population close to 1.5 million. Formerly the imperial capital of Japan, it is now the capital of Kyoto Prefecture, as well as a major part of the Osaka-Kobe-Kyoto metropolitan area.-History:...

. In late 1568, Masahisa joined Shibata Katsuie

Shibata Katsuie

or was a Japanese military commander during the Sengoku Period who served Oda Nobunaga.-Biography:Katsuie was born in the Shibata family, a branch of the Shiba clan . Note the differences between , , and the .Katsuie was the retainer of Oda Nobukatsu...

, Hachiya Yoritaka

Hachiya Yoritaka

was a Japanese samurai of the Sengoku period who served the Oda clan....

, and Mori Yoshinari

Mori Yoshinari

was a Japanese samurai of the Sengoku period and the head of the Mori family, who served the Saitō clan. The Saitō were the lords of the Mino province. When the Saitō clan were overthrown by the Oda clan Yoshinari and his family became retainers of Oda Nobunaga....

 in attacking Iwanari Tomomichi

Iwanari Tomomichi

was a Japanese samurai of the 16th century. Also known as Ishinari Tomomichi , he was a retainer of the Miyoshi clan, and held the title of Chikara-no-suke...

's Shōryūji Castle

Shoryuji Castle

is a castle in Nagaokakyō, Kyoto, Japan.-History:This castle was constructed in 1339 by Hosokawa Yoriharu, a major samurai commander under Ashikaga Takauji, the founder of the Ashikaga shogunate....

.

Later, Masahisa was also present at the Siege of Odani

Siege of Odani

The 1573 was the last stand of the Azai clan, one of Oda Nobunaga's chief opponents.Nobunaga took Odani Castle from Azai Nagamasa, who, left with no other option, committed suicide along with his son. His wife and three daughters were entrusted to Nobunaga, considering they were his sister and...

 (1573). In 1570, while under attack from Asai forces under Isono Kazumasa

Isono Kazumasa

was relatively the most senior of retainer beneath the clan of Asai throughout the latter Sengoku Period of Feudal Japan. Initially at the time in which Kazumasa began his service under the Asai, Sukemasa was the present head over the clan, and Kazumasa began his great line of feats by supporting...

, he lost his son Sakai Kyūzō

Sakai Kyuzo

Sakai Kyūzō was a retainer of Oda Nobunaga and son of Sakai Masahisa. He fought his first battle at age thirteen, and then fought another battle at the Siege of Odani Castle. In that battle, he was killed.- References :...

. Masahisa himself died soon after, at the Battle of Katada. Family headship was thus inherited by his 2nd son, Sakai Etchū no kami.