Lifespan: 15xx to 12/22 of Genki 3 (1573)
Other Names: Iwamuro Kanemon (?), (Yasaburō is a common name and his real name is unknown)
Lord: Oda Nobunaga → Tokugawa Ieyasu
Father: Katō Nobumori
Siblings: Nobumasa, Yasaburō
Katō Yasaburō served as a bushō during the Sengoku period. He was a retainer of Oda Nobunaga and, later, Tokugawa Ieyasu.
Yasaburō was born as the second son of Katō Nobumori of Atsuta in Owari Province. According to one source, he became the son-in-law of Iwamuro Nagato-no-kami and adopted the name of Iwamuro Kanemon.
Yasaburō was a member of the group of bushi acting as servants of Oda Nobunaga.
In the early Eiroku era (1558 to 1570), he became a member of the elite cavalry known as the akahoroshū who rode with red capes that filled with air to deflect arrows or other objects hurled at them in battle.
In the fifth month of 1560, Yasaburō joined Iwamuro Shigeyasu, Hasegawa Kyōsuke, Yamaguchi Hida-no-kami, and Sawaki Yoshiyuki on a rapid pre-dawn deployment with their lord, Nobunaga, for the Battle of Okehazama.
In 1569, at the Siege of Ōkawachi Castle in Ise Province, Yasaburō, Hida-no-kami, and others served as members of the group of hatamoto responsible for defending the main base and managing limited construction work. Thereafter, along with Kyōsuke, Hida-no-kami, and Yoshiyuki, he incurred the ire of Nobunaga and absconded from the Oda. They turned themselves over to the remit of Tokugawa Ieyasu. Based on the authenticated biography of Nobunaga known as the Shinchō-kōki, the group hid in Tōtōmi Province.
Alternatively, according to the archives of the Atsuta-Katō family, in 1563, Yasaburō fled after slaying a senior retainer of Nobunaga named Michimori. Following a period of wandering, he was engaged by Tokugawa Ieyasu for a stipend of 3,000 kan.
In the twelfth month of 1572, Yasaburō served in the Battle of Mikata-ga-hara, and together with the others in his group, was killed in action.