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"In any case," Iruka continued. "That's the real story behind the Kyubi's attack. That was the real reason for Ino's behavior back in class, and pretty soon it'll be happening to all the others, as well. I'm sure it already has for some of them. That's because after a child reaches the age of puberty the pheromone starts to take its effect on them, sometimes immediately, other times it's a delayed process. But when it does happen, it increases their sex-drive drastically. And since it's nearly impossible to suppress the urges in any way other than through sexual release, the Hokage lowered the age of adulthood for Konoha villagers to fourteen, and it became perfectly legal for them to start having sex with other people."

Naruto's eyes widened. "So you're telling me that now that I'm fourteen I could have sex with anybody I want? Or that anyone who wanted to could have sex with me?"

"Right, assuming they're also of age. Of course, they also have to be willing to do it with you, though to most people it's considered very rude to deny someone seeking relief from their unrelenting urges."

Naruto scratched his head. "How come I haven't had any of these 'urges' yet? I've already gone through puberty and everything, right?"

The other three looked a bit uncomfortable at the question. They of course knew the real reason why it might not have happened yet, but it wasn't something they were at liberty to talk about.

"I'm sure it'll be happening eventually, Naruto," Teuchi told him. "Sometimes it just takes longer for some than others. Hell I've known kids to get their first urge as early as eleven years old and as late as sixteen. My advice is to enjoy it while it lasts, because an almost endless need for sex isn't quite as fun as it might sound."

http://www.fanfiction.net/s/6549314/2/