Some TMNT stuff really isn't for little kids.
- This article is chiefly about the deceased human character and his identity across multiple lifetimes. For an article chiefly about Splinter, who retains Hamato Yoshi's identity and memories since reincarnation, see Splinter (IDW).
In his youth, Yoshi had difficulty controlling his temper, and often lashed out at other young men. After being forced to meditate overnight by a stream, he was surprised by Tang Shen, whose presence soothed his anger. They began a relationship, and soon married.
However, this relationship led to friction with Oroku Saki, his clan brother since early childhood, who believed that Tang Shen was supplanting the role that the Foot Clan should have in Yoshi's life. During a joint mission with Saki, Yoshi was badly wounded and barely made it home to Tang Shen, but rallied after she revealed that she was pregnant. She gave birth to their four sons in the next few years.
After criticizing Saki, who was the current Foot Clan Jōnin, Yoshi and his family were marked for death. After Yoshi found Shen dying from a strike by Foot assassins, Yoshi fled with his sons to the mountains and raised them as a single father, teaching them ninjutsu. But Oroku Saki caught up with them, and had Yoshi and sons all summarily executed.
Hamato Yoshi and his sons were reincarnated in the modern era as laboratory specimens of StockGen, the New York City-based biotech laboratory of Baxter Stockman. From the moment a rat named Splinter was injected with an experimental psychotropic compound to enhance his cognitive abilities, he could once again fully remember his past life as Hamato Yoshi. Once Splinter and four laboratory turtles (his four reincarnated sons) were mutated into a more human-like forms, Splinter embraced his new name and rodent identity, but would also continue to identify as Hamato Yoshi in full continuity with his past human life.