After years of being sheltered from the human world, the Turtle brothers set out to win the hearts of New Yorkers and be accepted as normal teenagers through heroic acts. Their new friend April O’Neil helps them take on a mysterious crime syndicate, but they soon get in over their heads when an army of mutants is unleashed upon them.
The wild experiments of rogue scientist Baxter Stockman end with his mutagen leaking into the sewers of New York, an accident that creates Splinter, the Ninja Turtles, and various other mutants. 15 years later, Splinter has trained his adoptive sons and himself in Ninjitsu, and despairs over the young Turtles’ fascination with all things human. Meanwhile, the Turtles concoct a heroic plan to announce their existence to the human world after meeting aspiring student reporter April O’Neil.