Born in 1485, Nagatomo headed the Tako clan, founded by Tako Sochō, fourth son of Utsunomiya Yoritsuna, and served as a branch family of the Shimotsuke Utsunomiya clan based at Tako Castle in Kawachi District. The castle sat on a key route from the Oyama and Yakushiji areas to Utsunomiya, making it the linchpin of the southern defense of Utsunomiya Castle. In 1558, a large army under Uesugi Kenshin, allied with Ashina Moriuji of Aizu, invaded Shimotsuke Province from Kozuke and attacked Tako Castle in an attempt to seize Utsunomiya. Nagatomo personally led his forces in fierce resistance, killing the vanguard commander Sano Toyotsuna among many others and routing the Uesugi army all the way to Shirai in Kozuke — the Battle of Takogahara. Nagatomo is said to have died later that same year.

A valiant commander who personally led the defense against Uesugi Kenshin's overwhelming force, and a loyal branch-family retainer who held the front line in defense of the Utsunomiya clan.

His stand at the Battle of Takogahara left Tako Castle remembered as a fortress in Shimotsuke that even Uesugi Kenshin could not take.