Fine, seeing as the guesses are rolling in again...
The element of main-character-plot-protection. Naruto mastered it ages ago, as did Sasuke.
then it must be gay-ness. or hate.
The next Generation of perverted ninjas is fully prepared to take their place. The line of the Toad Master will never fail as long as there is a will of fire. Rest In Peace Jiraiya-sama, this world and Tsunade were not good enough for you.
I am as far beyond you fanboys as you are above the humans.
Samurai Champloo & Raikiri too