Comics
In the original comic book version (TMNT vol. 1 issue 1 (May 1984), Hamato Yoshi was a high-ranking member of the Foot Clan in Japan. He owned a rat named Splinter, who copied his movements as he practiced ninjutsu. He was romantically involved with a woman named Tang Shen. However, their relationship attracted the jealousy of Oroku Nagi, who also loved Shen. When Nagi was rejected by her, he became enraged and violently beat her. Shortly after, Yoshi arrived and, in his fit of anger, murdered Nagi. He was dishonoured for having killed another member of the Clan and forced to choose between death or exile to the United States. He chose the latter, and left with Shen and Splinter. Years later, Nagi's brother Oroku Saki climbed the ranks of the Foot to become assigned the leader of its New York branch. He followed the two lovers to New York City and killed them both in vengeance of Nagi. However, the rat Splinter escaped to the sewers and mutated along with the Turtles. He then proceeded to teach ninjutsu to the Turtles as he himself had learned it from Yoshi, in order to have them avenge his owner's death.
In Tales of the TMNT #22, the turtles encounter a female ninja with a Shredder gauntlet on her arm; she vows to kill the turtles for crimes Hamato Yoshi committed against her family, but she is not a member of the Oroku family. This has the turtles wondering if Splinter was not telling them something.
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