Fifteen years has passed since the near-accident that changed the lives of one rat and eight infant turtles. Now, those same turtles: six brothers and two sisters, who are born as mutants in the sewers of New York, named after the masters of the renaissance and trained as ninjas by a rat, are forced to leave their destroyed childhood home in underground and take the first step into a surface world. In the surface, they're going through of many adventures and meet new friends from humans, from whom they were supposed to stay hidden due to being different to them. However, they also find the surface world a dangerous place and meet many foes in the form of the street thugs, criminal organizations, the deadly clan of ninjas and even monsters, until they meet their toughest opponent ever that is related to their past, The Shredder.