So, pedophilia (with those who have gone through puberty) ought to be socially acceptable because of cultural differences in the age of consent and because you're unsure of how easily teenagers can be taken advantage of? This seems to be more of an argument for coming up with a better way of measuring consent among people of differing levels of maturity than an argument for the social acceptance of pedophilia (with those who have gone through puberty).
The problem with your argument about the social acceptance of some ethical quandary differing among cultures (or is not universally accepted) is that other social systems of morality, such as slavery, were acceptable among cultures different than our own (our modern culture obviously being different than our past culture). Systems of morality or legal laws differing among cultures is not an argument
for abolishing that system of morality or legal law. Just because legal laws differ among cultures on slavery (past or present), for example, is not an argument
for slavery (if you think slavery is fine and dandy, replace it with genocide or cannibalism or something else that you find morally reprehensible but differs among cultures because I'm not interested in derailing this thread in that way).
Also, your argument for drawing the line at puberty is a tautology ("Children are children, and children shouldn't have sex.").
Also, while in Japan, the national age of consent is 13,
"prefectures can have
ordinances that prohibit sexual activities with any minor under
18."
http://en.wikipedia.org/wiki/Ages_of_consent_in_Asia#Japan
@thehabitatdoctor
I have not revealed my position on the matter, so I feel no responsibility to take on the burden of proof. I simply asked a question.