Masamoto Takeshi and a student of the Niten Ichi Ryu. He is the younger brother of Masamoto Tenno and a cousin of Akiko.
Yamato appears in the Way of the Warrior, the Way of the Sword and the Way of the Dragon. He is mentioned in later books also.
Yamato first meets Jack in Toba, where, at first he is hostile towards him. One day, Jack asks Yamato to teach him what he knows about kenjutsu. Jack learns under Yamato for a while before they begin dueling each other, sparking a fierce rivalry. Jack, during a later duel at the Taryu-Jiai, asked Yamato, "Best out of three?"
There Jack become rivals with Kazuki but Yamato doesn't step into defend him due to the fact he is still antagonostic towards his foster brother.
Later, Yamato runs away from Niten Ichi Ryu to join it's rival school due to the fact he has shamed his father after not stepping into help when rival students attack Jack and his friends. He joins the Yagyu Ryu, the Niten Ichi Ryu's rival school, in an apparent act to spite his father during the Taryu Jai.
In the competition, he beats Saburo and fights Jack to a draw in the kenjutsu segment. Later, both are ordered to retrieve the Jade Sword from the Sound of Feathers waterfall to determine the eventual victor. Yamato reaches there first, but due to his fear of heights, only progressed halfway up the steep cliffface, refusing Jack's offer for help. After Jack had retrieved the sword, the two quarrel again and Yamato lets go, plunging into the waters below.
Jack rescues Yamato from the river below, and the two reconcile. They make their way back, where Yamato initially appears to offer the Jade Sword to Kamakura, but gives it to Masamoto instead, telling him that Jack was the one that truly got the sword in the first place. As a result, the Niten Ichi Ryu are declared champions of the Tayru Jai, and Masamoto forgives his son.
During the festival, Jack, Yamato and Akiko try to stop Dragon Eye from his attempt to posion daimyo Takatomi, but they are no match for his skills, and Yamato is hit in the chest by a shuriken as he dives to protect Jack. Just as they are about to fall, Dragon Eye is alerted that the daimyo's forces are coming for him, and flees.
Masamoto later calls upon the trio and bestows upon them great gifts - for Yamato, he gives him his brother, Tenno's daisho.
Yamato, like several others, would compete in the selection trials for entering the Circle of Three. Unfortunately, he did not pass a single trial - failing the Trial by Wood, Trial by Arrow, and The Gauntlet. He would sink into despair for a while after failing to impress his father yet again, but soon would be revitalized by his newfound proficiency with bojutsu, with their blind Sensei Kano guiding him along.
Like Akiko, he disapproved with Jack's plan of hiding the rutter in Nijo Castle, where their daimyo resides, to avoid it being taken by Dragon Eye. Late in the book, the trio would secretly try to recover the logbook, but they were caught unawares by a kunoichi sent by Dragon Eye who attempted to posion them. In the resulting scuffle, Yamato was knocked out by Dragon Eye's kunoichi, and Akiko poisoned. Jack put up a fight, but was unable to stop Dragon Eye from taking the rutter. Masamoto later finds out about the incident, and expels Yamato along with Jack and Akiko from the Niten Ichi Ryu.
Yamato joins Jack and Akiko in their pursuit of Orochi, a man who supposedly had information about Dragon Eye. They eventually catch him, and manage to find out that a ninja clan has settled on the west side of the Iga Mountain range near the village of Shindo. Before Orochi says much more, a ninja kills him by way of posion dart. They would be briefly split up by the ambush, but Yamato finds Jack safe and sound later, unaware that Akiko, dressed as a ninja, saved him from his assaliant. Yamato and Jack question one of the fallen ninja, asking for the whereabouts of Dragon Eye, but before they can get any information the ninja commits suicide. Jack takes a tanto from the ninja's corpse which he later finds out is a supposedly cursed blade, make by an evil swordmaker called Kumitone.
Yamato, Jack and Akiko visit the village of Shindo in an attempt to recover more information about Dragon Eye's whereabouts, and find Kumitone. They discover that the village is close to being a ghost-town and that Kumitone has supposedly killed himself with his own blade. According to one of the last remaining villager, Kumitone's spirit remains and has cast a "dark shadow" over Shindo.
The trio visit The Dragon Temple in Shindo to search for more information and find an old woman inside, who in exchange for money, gives them the information they are searching for. In reality Kumitone had not killed himself, but had still been killed by his own blade. He had forged a new sword, named Black Cloud, for one of his clients, and the sword was the deadliest in existence. The client (revealed to be Dragon Eye), was so impressed with the sword, he decapitated Kumitone to ensure that he could not forge a sword that would rival Black Cloud. They also discover that Dragon Eye is in fact exiled samurai lord Hattori Tatsuo. He apparently gouged out his own eye because it became infected with smallpox, and his remaining eye turned green when his mother attempted to poison him. In revenge Dragon Eye gouged both of his mother's eyes out. The woman who gives the information to Yamato, Jack and Akiko is inferred to be Dragon Eye's mother when she reveals two empty eye sockets.
After having their positions at the Niten Ichi Ryu as samurai reinstated, they get back their weapons and resume training. Since Yamato was not qualified for Two Heavens training, having failed the selection trials for the Circle, he did not get that privilege.
Initially Yamato is very brooding in nature and is antagonistic towards Jack. He tries his best to please his father and live up to his elder brother's name.
Yanato is described as having black, spikey hair and chestnut brown eyes.
- Bojutsu Expert-Yamato proved to be a natural with the bo, picking it up quicker than anyone else in Sensei Kano's classes, and using it to great effect against enemies such as Dragon Eye.
- Kenjutsu Practitioner- Yamato has some skill with a bokken, however, it is not shown what his true level of proficiency is, as he has never really wielded a katana before.
- Taijutsu Practitioner- Yamato is skilled in taijutsu to some extent, beating Saburo quickly in the Tayru-Jiai and beating Jack in chi sao.
- Bo staff - Yamato is very skilled with his bo staff and is Sensei Kano's best pupil.
- Katana - Though it isn't shown much in the books, Yamato can use the katana to some extent.
- Masamoto Takeshi - Yamato always tries his best to make his father proud and is devestated whenever he fails to do so. Both son and father love one another but don't always show it very well.
- Jack Fletcher - at first their relatioship is rocky one, Yamato refusing to accept that Jack was a place in his family. Later, they grow to become the best friends, finally reaching a relastionship where they are practically like brothers.
- Masamoto Tenno - not much is known about Yamato's relationship with his older, deceased brother but it can be gathered that Yamato looked up to and admired him.