Hida Tadamasa served as a bushō during the Sengoku and Azuchi-Momoyama periods. Tadamasa was a retainer of the Oda clan and served as the lord of Yoneda Castle in the Kamo District of Mino Province.
His ancestors were descendants of the Shinano-Suwa clan and served Minamoto no Yoshinaka, a bushō from the Shinano-Genji family during the end of the Heian period. In the era of Hida Tadanao, after moving to the village of Hida in Mino, the family resided in Fukushima in the Yoneda manor and adopted the surname of Hida. Alternatively, the clan was of the lineage of the Mino-Genji and, after a period under the name of the Toki clan, later adopted name of the Hida clan.
Tadamasa was born as the son of Hida Tadanao. Initially, he was in Fukushima Castle constructed by Tadanao on Mount Gongen, but, in 1560, moved to a built Yoneda Castle on Mount Kamo.
In the eighth month of 1567, when his son, Chōjumaru, attempted along with 300 soldiers to eliminate Mōri Kanemon from Mōriyama Castle, a group of Kanemon’s retainers murdered their unpopular lord and surrendered so Chōjumaru entered the castle without a battle and took over governance of the territory. During the Genki era (1570 to 1573), in the third month of an unspecified year during this era, Chōjumaru entered into an alliance with Kishi Nobuchika, the lord of Dōhora Castle and agreed to exchange Mōriyama Castle for Uma-no-kushiyama Castle which was in an enclave controlled by the Kishi.
After Oda Nobunaga invaded Mino and prevailed in the Battle of Dōhora, Tadamasa received recognition of his former fief and appears to have quickly obeyed Nobunaga. According to the authenticated biography of Nobunaga known as the Shinchō-kōki, while the timing is uncertain, Tadamasa served along with Mori Yoshinari in the vanguard of a battle against Takeda Shingen after the Takeda invaded Kōyaguchi. In the ninth month of 1570, Tadamasa joined Mori Yoshinari and Oda Nobuharu to defend Usayama Castle. An assault by the combined forces of the Asakura and Azai led to the deaths in battle of Yoshinari and Nobuharu, but Tadamasa, together with Mutō Gorōemon and Hida Hikozaemon desperately defended the castle.
In the spring of 1582, Mori Nagayoshi, the lord of Kanayama Castle, sought the transfer of Uma-no-kushiyama Castle, but Tadamasa declined the request. On 6/2 of Tenshō 10 (1582), in a coup d’état known as the Honnō Temple Incident, Oda Nobunaga, together with three younger brothers of Nagayoshi including Mori Naritoshi were killed. Under the pretext of holding a memorial service for his three brothers, on 6/22, Nagayoshi deployed to launch a surprise attack against Yoneda Castle. Inside the castle, no preparations for a battle had been made as the occupants were engaged in a boy’s birthday celebration. Tadamasa fled with his wife and children, but, while running to catch-up with them, Chōjumaru was shot and, after reaching his parents, perished. After placing his wife and other son in a safe location, Tadamasa relied upon Saitō Toshitaka, the lord of Kajita Castle, to confront the Mori army near Ushigahana, but was defeated. Retainers including Itō Tadasuke and Tada Kakuemon were captured. Later, these two became retainers of Nagayoshi and, along with Nagayoshi, died in the Battle of Komaki-Nagakute.
According to one account, Tadamasa was killed by Ōshima Mitsuyoshi, but, at this time, Mitsuyoshi was aligned with the Saitō and fighting against Nagayoshi. Other theories include that he took his own life inside Kajita Castle, or that he turned to Satō Hidekata, the lord of Nataoyama Castle who was a relative of his father-in-law, Kanamori Nagachika, and later died of illness in that territory. According to yet another record, he affiliated with Hashiba Hideyoshi after the demise of Oda Nobunaga.
Tadamasa’s son, Tadachika, was immature, so he was raised by his grandfather, Kanamori Nagachika. After Tadachika grew up, Nagachika had him meet Tokugawa Ieyasu in person. Tadachika was a member of the yorai, a collegial body comprised of members of military families. He received from Ieysau landholdings of 1,000 koku including the Gokuraku Temple, Ikushi, and Shimouchi in the Mugi District. Continuing with his son, Tadayori, and thereafter, the Hida served the Tokugawa shōgun family for generations. The lineage of Tadayori’s younger brother, Hida Tadatora, served the Owari-Tokugawa family.