Ancient One (2003 TV series)

The Ancient One is an old ninjitsu master who taught Hamato Yoshi.

Biography
In the Post-World War II era, when Japan is still recovering from its defeat, it is not uncommon to see young orphans begging in the streets. Hamato Yoshi and Yukio Mashimi found a coin that the Ancient one dropped. Mashimi wanted to spend but Yoshi gave the coin back. The Ancient One, pleased with the boy's kindness, offered to give it back if they could swipe it from his hand; the former failed but the latter succeeded. He took the two boys into his home, where he trained them in the ways of ninjitsu like his own sons. He also adopted another orphan girl Tang Shen, who the boys fell in love with but she fell in love with Yoshi.

When the boys became men, they saved Mortu from the Foot Clan when they discovered his Utrom nature, he offered them the chance to become Guardians. The Ancient One forbaded them because he sees they need mental training. But as men, they made their decision and became Guardians. The Ancient One went with Yoshi to ask the Ninja Tribunal to ally with the Utroms against the Shredder impostor but the latter refused as he was not the true Shredder, ignoring the possibility that Ch'rell could challenge his namesake.

Unfortunately, Ancient One failed to see that Mashimi became angered at his lack of success as a Guardian and losing Tang Shen to Yoshi. He killed the latter and revealed the Utroms' location to the Shredder. When Yoshi killed him, he left Japan to go to New York, naming his rat Splinter.

Years later, the Ancient One would encounter Splinter once again, in a more evolved humanoid form. The Ancient One was surprised, assuming him to be a demon until he learned who he truly was. He couldn't accept that Yoshi was dead. He went to the Lap of the Gods to tell the Tribunal of Yoshi's loss; they were unconcerned. But unbeknowst to him, he had led a bone demon to the sanctuary, guided by the Foot Mystics to locate the original Shredder's remains. But as Splinter's young turtle sons could see him, broke the necklace that made him concealed to all but the young and pure. The Ancient One and Splinter defeated the demon. the Tribunal then erased the young ones' mind of the recent events to protect them. Before departing, the Ancient One gave the young turtles ninja masks.

Years later, the Ancient One patiently awaited Leonardo's arrival to guide him to the right path, for the young turtle blamed himself for letting his family get hurt at the hands of the Utrom Shredder and became more aggressive and cold. The Ancient One didn't reveal his identity to the turtle in the journey to his other home. He calmly told Leonardo to let ghost demons defeat him. at his temple, he showed Leonardo's greatest enemy -- himself. Leo comes to the revelation that the Ancient One was right beside him the whole time. He took Leo under his tutelage, teaching him wisdom and greater skills. But while meditating, the Ancient One had a premonition of the new Shredder, Karai and told Leo to go back and save his family.