Isao Moto

Background
Isao was born to a pair of samurai roughly a decade prior to the 4th Shinobi world war. He was always a serious child, preferring to train to become the best samurai he could instead of playing like the other children did. Despite this he still made a few friends here and there. At the age of 7 he was apprenticed to one of Mifune's eldest, and most unscrupulous, students. Isao was regularly given packages to deliver to various contacts of his master. However during one of his deliveries, the contact became unruly. Though Isao successfully defended himself, his left eye was damaged in the process. He successfully managed to sneak back into his master's chamber where it was replaced by the eye of recently deceased samurai with a similar eye color. While the eyes weren't the exact same color they were close enough to pass it off as his natural eye.

Isao participated in the 4th war in a non-combatant manner. While he was on the battlefield he never once saw combat. He was instead assigned to bring the bodies of dead and injured ninja back to the medical corp. While he was at this he also ransacked the corpses looking for valuable intelligence and scrolls.

After the war, Tsunade retired after allowing Naruto to take the Kageship. However after the ceremony where she relinquished the title of Hokage, a messenger met her. He was from the samurai in the Land of Iron. They asked her if she would travel to the land of iron to teach them medical ninjutsu as well as to help heal those samurai who had yet to recover as well as teach them how to better counter stronger ninja. Tsunade, not willing to waste her last few years after wallowing for decades in self pity, agreed. She traveled to the Land of Iron and quickly got to work. Isao was one of those she looked at. She recognized the fact that his eye was a transplant, and asked Mifune about him, He told her the story of how his eye had gotten injured as he had found out about his former student's dealings and that he had taken him upon himself to train the boy. Mifune asked her to help him gain strength in a way that would not be a shortcut like his eye he had gained without any real effort would be. He explained that as a student he trained for hours upon hours each day, all so he could be a great samurai like his late parents were. Tsunade watched him the next day as her medical class was practicing their newfound mystical palm technique. She was reminded of a certain other hard headed young man whose life she had changed, Rock Lee.

The next day she agreed to help teach the boy. Under her tutelage he learned the mystical palm and various other medical ninjutsus, culminating with him storing chakra for several years to acquire the yin seal and learning her regeneration techniques. However the stipulation that he must never use those techniques unless his comrade's lives depended on it was placed on the usage of creation rebirth and the strength of a hundred seal. The seal was designed to be his ultimate shield in protecting his comrades in honor of the hundreds if not thousands of samurai who had lost their lives during the 4th war. In addition, she also taught him how to open the first two gates properly. This occurred after he managed to accidentally open one after almost falling off the mountain during one particularly intensive training exercise. This move also carried the stipulation that it must only be used when one absolutely had to be destroyed in order to save the world. This was in honor of all the ninja who gave their lives along side of them. His life wasn't worth any less as she had seen thousands of ninja and samurai die too young during the 4th war.

After all of Tsunade's regeneration took its toll and she passed away, Isao spent the next decade learning how to open 5 more of the gates, leaving the total number of gates he could open at 7. During this same period, the Oda Genji split off and took most of the samurai with it. Upon Mifune's request Isao stayed in the force of samurai that was still members of the Land of Iron. The members who had stayed left 3 wolf mountain except for the few who were left behind to maintain an "official" presence there and moved into the capital of the Iron. After another 10 years of training, Isao managed to learn to open the 8th gate as well as trained his body to the point where the lesser gates didn't affect him as much.

While Isao was at the age of 33, 23 years after the end of the 4th Shinobi World War, the current leader of the remaining Land of Iron Samurai's health was failing. He was well into his 60s and didn't have much longer. He held trials to determine the strongest samurai to replace him. After defeating 127 different contestants during the course of the trials Isao won. He had achieved this feat in a baffling way. During the entirety of the fight he had not once drawn his blade, fighting numerous skilled opponents with nothing but his bare hands. Even with such a massive handicap, he had only once been forced to use even the first gate, and even that was only during the final match against the strongest competitor besides himself. Despite his self imposed handicap Isao ended up becoming the next leader of the Iron Samurai, a position he has held for the last 7 years...