Teenage Mutant Ninja Turtles: The Supreme Mutation

Premise
Set in a fictional metropolis called New Yorkyo (a portmanteau inspired by New York and Tokyo), the Turtles were initially trained by Master Splinter, whose one of the great masters.

Plot
As the story goes, the four Turtles were exposed to the mutagen when after a traffic accident with their young owner as a bystander. The mutagen mutated them into a more human form and more developed intellect. Hamato Ruko (Splinter), a student once trained by his father Hamato Yoshi was also exposed. Hamato Ruko becomes a humanoid rat, Splinter. Splinter was fantastically smart and learned Ninjutsu by mimicking his master. Hamato Yoshi moved from his hometown to New Yorkyo. However, Yoshi was found and killed by Oroku Saki. Saki was the leader of the New Yorkyo branch of the Foot Clan and had taken the identity The Shredder. Yoshi's death had left Hamato Ruko (Splinter) homeless.

Hamato Ruko (Splinter) happens to see the Turtles after the accident and adopts them. Within days, Turtles grow to human size and develop speech and Hamato Ruko turn into a humanoid rat. Splinter retreats to the New Yorkyo sewers where he raises the four turtles as his sons and imparts to them his knowledge of ninjutsu. Splinter trained them in Ninjutsu, so they could avenge the murder of Hamato Yoshi. He also chooses their names from a book about Renaissance artists: Leonardo, Donatello, Raphael, and Michelangelo.

Now teenagers, the Turtles venture to the surface for the first time and learn that the Triceratons are using the mutagen as part of their plan to take over New Yorkyo. The Turtles befriend the famous singer, April O'Neil after she is abducted by the group of street thugs, the Purple Dragons after witnessing them stealing equipment. Raphael's sai is then thrown into the street light and the four turtles defeat and tie up the attackers, saving April.

The Turtles also learn that Splinter's long-time enemy Oroku Saki (Oroku Saki) has ordered Foot Clan to track down Splinter and his sons, and put an end to their clan.