Leonardo, often referred to as Leo, is one of the main protagonists of the 2012-2017 television series and the leader of the Teenage Mutant Ninja Turtles. He is also the oldest of the four brothers, who share a home in the underground sewers of Manhattan, New York City. Leonardo is Master Splinter's adopted son and Karai's adopted brother. He belongs to a diverse family consisting of three other mutant turtles who are his younger biological brothers: Raphael, Donatello, and Michelangelo.