April O'Neil, ace reporter for Channel 6, investigates recent break-ins, allegedly by Ninjas, which have resulted in the thefts of numerous technologies. However, a chance encounter with a gang of thieves soon leads her to a bigger story when she is saved from the criminals by four Ninja-trained, mutated Turtles.
The Turtles take April back to their lair, and, after getting better acquainted, April learns they are good-hearted mutants. They decide to investigate the thefts together, and their efforts lead them into an encounter with the mysterious ninjas, The Foot Clan, and their leader, Shredder.