Utsu Tadatomo served as a bushō during the Sengoku period.  He was a retainer of the Matsudaira clan of Mikawa Province.

In 1506, when a huge army led by Imagawa Ujichika invaded Mikawa, upon observing the size and scale of the enemy forces commanded by Ise Moritoki (a tozama, or outside daimyō, later known as Hōjō Sōun, a sengoku daimyō and founder of the Gohōjō clan), Tadatomo proposed to restrain the advance of allied forces and to wait for an opportunity to catch the enemy off-guard to repel them.  He further advised his lord, Matsudaira Chikanaga, to pacify Mikawa through the exercise of benevolent rule.

In the era of Matsudaira Nobutada, some individuals backed an illegitimate son named Matsudaira Nobusada as the designated successor to Nobutada, but Tadatomo did not agree.