After being mutated froma turtle to a mutant, Leonardo and his brothers met up with another mutated animal - Splinter and learned the ways of Ninjitsu. They now fight for the evil Shredder and try and stop him from destroying them and conquering the Universe.Leonardo, in my opinion is a very on task, organized type of turtle. All though his characteristics constrasted most of the other turtles it didn't lower his "Ninja Turtle" fighting ability - for he can fight with the best of them. He trains much with his Katanas and without, which allows him to be very worthy fighter and barely ever will you see him not ontop of his opponent. Splinter gave Leonardo the role of Turtles leader which may be the reason some see him as really uptight. With having so much responsibilty of having to control everything, he is not always a fun-loving guy and sometimes he tries to control too much. But in the end, he's a turtle so you gotta love him.