Hirano Nagayasu served as a bushō during the Azuchi-Momoyama period and hatamoto, or direct retainer fo the Tokugawa shōgun family, during the early Edo period.  He is known as one of the Seven Spears of Shizugatake for his valor fighting for the Toyotomi in that battle.

The Hirano clan originated from the Yokoi clan, an illegitimate branch of the Hōjō clan who were regents to the shōgun of the Kamakura bakufu said to have descended from Kanmu-Heishi no Naokata from the middle Heian period.

The Hirano family adopted its surname from the name of the village of Hirano in the Nakashima District where it possessed land after becoming residents of Tsushima in the Kaitō District of Owari Province.

In 1559, Nagayasu was born as the third son of Hirano Nagaharu.  His common name was Gonpei.  His first real name was Nagakatsu.  Nagayasu wed one of the daughters of Hijikata Katsuhisa, a retainer of the Oda and, later, the Toyotomi and Tokugawa families.

Nagayasu’s father, Nagaharu, was originally named Funabashi Ukyōnojō, later becoming the adopted son-in-law of Nagayasu’s maternal grandfather, Hirano Bankyū-Nyūdō.  Owing to this history, Nagayasu did not carry the bloodline of the Hōjō clan through his father, only that of his mother.

In 1579, similar to his father who served as a retainer, Nagayasu served a young Hashiba Hideyoshi.  In 1582, after the coup d’état against Oda Nobunaga known as the Honnō Temple Incident, Hideyoshi and Shibata Katsuie came into conflict over succession to the Oda clan.  In 1583, when the two factions engaged in a decisive conflict at the Battle of Shizugatake, Nagayasu joined Fukushima Masanori and Katagiri Katsumoto to serve valorously in the front lines for which he received recognition as one of the Seven Spears of Shizugatake.  Owing to these contributions, he was awarded a fief of 3,000 koku in Kawachi Province.

On 4/9 of Tenshō 12 (1584), at the Battle of Komaki-Nagakute, when Hashiba Hidetsugu fled in defeat from Nagakute, Nagayasu charged the enemy forces and captured heads.  On 5/1, in a battle at the Futaebori fortress, Nagayasu fought valiantly.  In the eighth month of 1595, his fief was increased by 2,000 koku and he was granted a fief of 5,000 koku comprised of seven villages near Tawaramoto in the Toichi District of Yamato Province.  On 3/15 of Keichō 3 (1597), Nagayasu was awarded the title of Junior Fifth Rank (Lower) and Governor of Tōtōmi and conferred the Toyotomi surname.

In 1600, Nagayasu participated in the Conquest of Aizu led by Tokugawa Ieyasu.  At the Battle of Sekigahara, he joined the Eastern Army, serving in the Nakasandō division under Tokugawa Hidetada.  Nagayasu, however, did not arrive in time for the main battle so he did not have the opportunity to produce notable achievements.  Thereafter, he served under Hidetada and, in 1612, was involved in the construction of the Nijō palace in Kyōto for which he received further recognition.

In 1615, at the Siege of Ōsaka, Nagayasu suddenly absconded and attempted to converge with the Toyotomi to whom he had prior allegiance.  He made a direct appeal to Ieyasu, but was not permitted and, instead, ordered to serve as a guard in Edo in the absence of other forces.  Thereafter, he did not cause further trouble and, while serving as a hatamoto, or retainer of the shōgun family, was appointed as one of the otogishū, or retinue of elders, serving Hidetada.  Nagayasu led a long life, later serving Tokugawa Iemitsu, the third-generation shōgun of the Edo bakufu.  In 1628, Nagayasu died at the age of seventy.

With respect to his descendants, his bloodline ended with the third-generation Hirano Nagamasa, who, upon orders of Tokugawa Ietsuna, was adopted by Hirano Nagakatsu.  His heirs continued until the Meiji period.