Niiro Tadamoto served as a bushō from the Sengoku period to the early Edo period.  He was a retainer of the Shimazu clan, the sengoku daimyō of Satsuma Province in southern Kyūshū.

In 1526, Tadamoto was born as the son of Niiro Sukehisa.  The Niiro were a branch of the Shimazu clan of an illegitimate lineage.

In 1538, at the age of thirteen, he was taken by his father to serve under the watch of Shimazu Tadayoshi.  Thereafter, he served two generations of clan leaders – Shimazu Takahisa (the fifteenth head) and Shimazu Yoshihisa (the sixteenth head).  In 1545, during an attack against Irikiin Shigetomo (the twelfth head of the Irikiin clan), Tadamoto felled a mounted soldier from the Irikiin clan in a one-to-one contest, contributing to their victory.  In 1562, he participated in the attack on Yokogawa Castle.  In 1569, he attacked Ōkuchi Castle defended by Hishikari Takaaki who entered after Akaike Nagatō, and even though he incurred an injury, he charged into the battlefield, earning the reputation of being “as brave as a fierce god.”  Later, he served as the jitō, or steward, of the Ōkuchi area in Satsuma.

In 1572, Tadamoto had an active role at the Battle of Kizakibaru, and, in 1574, offered himself as a hostage to compel the surrender of an enemy commander who had held-out in Ushine Castle for over one year.  In 1581, Tadamoto joined in the attack on Minamata Castle, and, in 1584, at the Battle of Okitanawate.  He also advocated for stiff resistance against the invasion by Toyotomi Hideyoshi known as the Subjugation of Kyūshū.  He did not surrender to Hideyoshi until after the surrender of Shimazu Yoshihiro, the younger brother of Tadamoto’s lord, Shimazu Yoshihisa.

During the deployment to the Korean Peninsula, he was assigned to remain in Satsuma to protect the territory.  At the Battle of Sekigahara, after the return to Satsuma by Shimazu Yoshihiro, he learned that Katō Kiyomasa had invaded Ashikita.  He quickly returned from Kagoshima to Ōkuchi Castle and strengthened defenses on the border to prepare for an attack by the enemy forces.  Around the winter of 1610, Tadamoto became critically ill, and, despite wishes of recovery from Yoshihisa, Yoshihiro, and Iehisa (Tadatsune), he died in Ōkuchi Castle at the age of eighty-five.

During an invasion of Hizen Province, his eldest son, Niiro Tadataka, was killed in action.  Meanwhile, in 1603, Tadataka’s son and designated heir, Niiro Tadamitsu, died at an early age.  Therefore, after Tadamoto’s death, the headship of the clan was inherited by Niiro Tadakiyo, the son of Tadamoto’s second son (Niiro Tadamasu) who was the adopted son-in-law of Tadamitsu.

Anecdotes

Tadamoto was small but sturdy in stature, and praised by Shimazu Tadayoshi as one of four individuals in the Shimazu clan who would be remembered in the place where scriptures are read.  According to one account, if counting by your fingers, Tadamoto would be the first to identify as a warrior among the Shimazu clan, giving him the moniker of Musashi the Thumb.  While possessing the name as Musashi the Demon, he was also a cultured individual with knowledge of waka, renga, Chinese poetry, and the tea ceremony.

When surrendering to Toyotomi Hideyoshi, Tadamoto came forward with a shaven head.  When asked whether he would continue fighting, he responded by asking who should he oppose, but since Musashi (he) was a bushi, if his lord were going into battle, he would join at any time.  He further said that you (Hideyoshi) must be feeling secure.  If Yoshihisa promised even one time to submit, he would definitely not betray you.  This exchange revealed the honor of those from Satsuma.

After the Battle of Hetsugigawa, despite continued fighting, a retainer of the Chōsokabe named Tani Tadazumi came to accept the remains of Chōsokabe Nobuchika who was killed in action.  On this occasion, Tadamoto shed tears while apologizing for the death of the enemy general and arranged for a monk to accompany them on the trip back to Okō Castle in Tosa Province in Shikoku.

On new year’s day in 1596, Tadamoto, together with Machida Hisamasu and Chōsokabe Nobuchika, drafted life principles for those in the bushi class in Satsuma.  These later became the foundation for a code of education emphasizing respect, obedience and honor known as the gojū in the Edo period.

Upon the death of Tadamoto, two individuals martyred themselves notwithstanding a prohibition against martyrdom.  Moreover, as many as fifty others without permission to become martyrs cut their fingers instead.

Tadamoto was said to have planted three Japanese fir trees in Isa, with one of them lasting an estimated 400 years and growing over 25 meters in height.

Interests in classical poetry (waka and renga)

There are numerous anecdotes that, while on deployment, Tadamoto read from a compilation of waka by the light from the firing of arquebuses.  While attacking Minamata Castle, a hilltop fortress surrounded by plains in southern Higo Province, in the course of shooting, Tadamoto recited the poem “leaves from the trees in Minamata fall in the autumn wind,” and, while returning fire, an enemy commander named Indō Yoriyasu recited the poem “breaking waves in the inlet under the setting moon.”

After the formalities of surrender, a drinking party was held.  Seated nearby was Hosokawa Yūsai, who, after holding-up Tadamoto’s grey mustache while taking a drink, recited a poem that a pine cricket was under his nose, while Tadamoto responded with another verse that above his mustache the pine cricket chirps, impressing the generals in attendance.

At the banquet for Shimazu Yoshihiro and Shimazu Hisayasu (father and son) prior to their deployment to the Korean Peninsula, he recited a farewell poem for them.