The Hamato Clan dwindled in size, wealth, and influence compared to their peak in the Edo period. But it was their ability to adapt to whatever situation presented itself that enabled them to last into the late 20th century. Hamato Yuuta faced the same dilemma that had cursed his ancestors when a simple offer was proposed by The Demon: join his League of Assassins willingly or be forcefully assimilated.
Whatever honor remained died, but it was a calculated move that had been done countless times centuries ago. It was how the Hamato Clan survived the Sengoku period, thrived during the Edo period, and consolidated its power in the Meiji era. And as a reward for their cooperation, the league granted them greater autonomy and access to resources that were normally restricted to sub-organizations. The privilege wasn't squandered.
>On his deathbed, Yuuta believed he had brought honor back to his clan. He left the world comforted that his sons were destined to usher in a golden age. Hamato Yoshi leads the Hand clan while Oroku Saki leads the Foot clan upon their father's death. Almost immediately, the already existing sibling rivalry intensifies to the point that it begins to affect their efficiency. And it all comes to a head one day.
>The Demon assigns the Hand and Foot clans to monitor StockGen, a scientific research company front, regarding their latest research and experiments. It's there that Yoshi and Saki learn the owners and head scientists, Robert and Baxter Stockman, have developed a mucilaginous substance that enhances any creature's size, strength, and intelligence. Yoshi then discovers and captures a corporate saboteur from a rival firm, TCRI, who gets caught in the middle of wiping out both main and backup data on the research.
>After a lengthy interrogation conducted by Saki, they learned of a hypothesis proposed by Baxter that theorized the mutagen, if modified enough, could mutate humans as well. But it is initially dismissed by Robert. Intrigued, the Demon commands that the hypothesis be explored and grants the necessary funding for it to be presented. The deadline arrives with a promising development. Baxter requests the saboteur as the test subject for the mutagen, much to his father's disapproval. The Demon allows it.
>Yoshi watches in surprise as the saboteur gets covered in the substance and then disturbingly transforms into a humanoid scorpion. Baxter proclaims his hypothesis a success and explains how it combines with human and animal DNA to create a hybrid that does not compromise human intelligence. Saki believes it to be a key instrument to rewriting the world, which the Demon agrees with as well. Yoshi...
>A duel between brothers occurs and eventually ends in the sewers in New York City. Yoshi wins but gets exposed to the mutagen by one of his brother's dirty tricks. He painfully transforms into a brown rat, one that he almost tripped over earlier in the fight. When he awakes, he sees four baby turtles standing over him. Yoshi goes back to the surface in an attempt to contact his clan for help, but it ends with a cop firing on them out of fear and sheer incompetence. Yoshi decides right there and then to rise and teach them via exile.
