Leader of the TMNT, skilled swordsman and tactical genius.
Splinter serves as Leonardo's adoptive father, teacher, and spiritual guide.
Splinter is described as the turtles' adoptive father and sensei. He trains Leonardo in ninjutsu and later gives him a final lesson through a vision.
The brothers share loyalty but clash over leadership and responsibility.
Raphael argues with Leonardo over leadership at April's apartment, while the plot presents both as members of the same turtle family.
They are brothers and coordinated teammates within the turtle family.
Leonardo and Donatello are both members of the four-turtle team trained and raised by Splinter.
April becomes a human ally of Leonardo and the turtle team.
Leonardo and the turtles save April from thieves, protect her during the Foot attacks, and return to the city after Splinter's final lesson.
Casey becomes a practical ally to Leonardo's rescue mission.
Casey aids the turtles in fighting off the Foot and later helps free Splinter from the Foot hideout.
Shredder directly challenges Leonardo as the turtles' leader.
Shredder fights the turtles on a rooftop, overpowers an infuriated Leonardo, and attempts to kill him.
Explore the full interactive character relationship map of Teenage Mutant Ninja Turtles
Related entry on Wikidata (Q106540654), public domain (CC0).