Oniniwa Tsunamoto

Oniniwa Tsunamoto (1549-1640) was a senior retainer of the Date clan who served two generations, from Date Terumune, the father of Date Masamune, to Masamune himself. He played an important role in both the political and military affairs of the Date clan from the Sengoku period into the early Edo period. As a magistrate (bugyō) and councillor (hyōjōyaku), he demonstrated his skill in diplomacy and administration.

Tsunamoto enjoyed the deep trust of Date Terumune and was responsible for the military and administrative core of the Date clan. Even after Masamune succeeded, he continued to be valued. In 1590, when it came to light that Masamune had incited the Kasai-Ōsaki Uprising, he was dispatched to Kyoto to offer an explanation to Toyotomi Hideyoshi, and from then on he served as Hideyoshi's negotiator. In Bunroku 1 (1592), it is said that Hideyoshi had him change his family name to Moniwa, on the grounds that 'an oni in the garden is inauspicious.'

In the Battle of Sekigahara (1600), he sided with the Eastern Army and took part in the attack on Uesugi territory. After the war, as a councillor (hyōjōyaku) of the Sendai Domain, he stood above the six magistrates, and as Masamune's confidant he devoted himself to stabilizing the domain's governance. Tsunamoto lived to more than ninety years of age, an unusually long life for a Sengoku warrior, and his experience and knowledge contributed greatly to the management of the Date clan in the early Edo period.

In connection with arms, when he fled the Date clan in 1595, Tokugawa Ieyasu, who sympathized with his circumstances, gave him gifts including a spear with a bird-feather scabbard. This spear survives today, and in 1973 it was designated a cultural property of the town of Matsuyama (present-day Ōsaki City).