sexual orientation
"Being attracted to a group of people who cannot give consent" is not a sexual orientation; it is a mental disorder. Please stop making false equivalences with homosexuality; it is incredibly insulting.
The problem is that "Being attracted to a group of people who cannot give consent" is not equivalent to pedophilia. Remember, in this case, it's the body of a child that is attractive, not it's inability to give consent. Being aroused by the very fact someone can't give consent is indeed a mental condition, but pedophilia is just being attracted to children before puberty. If someone
looks the part, but are otherwise fully capable of giving consent, that's not going to be a problem for a pedophile (indeed, that would be the ideal solution of the problem). That's why it's quite a tragic situation to be in, too. Pedophilia is a sexual orientation, but one that can, like zoophilia (believe me, there's a movement in Germany that's trying to get
that legalized...), has a problem of unavailability of consenting partners.
That's why "conventional" punishments or even psychological help rarely works in such cases. Actual pedophilia is not a mental disorder, though child molestation can also result from a number of psychological problems and is a wider issue than pedophilia itself.
Of course all Japanese men aren't perverts, but Japanese culture is deeply problematic.
Remember that from their point of view,
we are weird. Japanese, as well as the other cultures in the region, are very, very different from us. So, the question is, can we judge them by our own values? Their view of sexuality, honor, heck, even of human life and it's value is fundamentally different from ours. Better or worse? Well, that's impossible to say, at least for a human. All culture is, by it's nature, highly subjective. Each of them is probably best suited wherever they evolved in. As such, trying to transplant a different culture in a place where there already is one is a very morally shaky endeavor, since it usually loses unique mechanisms used to better adapt to environment, and also brings it's own, often useless in the new environment. That has been known to do harm, though cultures are though to uproot and old elements trickle back in, sometimes even being transplanted back.
As such, the Japanese and their culture are probably best not messed with by outsiders. Their very way of thinking is almost completely alien to us. They can be understood, but it's hard, and pretty much requires spending a good chunk of life there.
Clearly you haven't looked closely at the majority of other humans. 
Well, I'm not saying everybody is pleasant to look at.
But that's somewhat irrelevant. Heck, some people can look traumatizing even in a full morning dress, which is an achievement considering how snazzy those look.
But that's beside the point, on an average man (or woman), nudity is not that unpleasant to look at once you get rid of sexual connotations. Now, old people and people with various diseases might be worse, but they probably wouldn't want to go out naked anyway, for other reasons. Of course, a clothed person will usually look better than an unclothed one, if they're not wearing a potato sack, at least. Most of our clothes are, afterall, not only meant to cover our bodies, but also make us look good, mask imperfections and convey various messages. There are, of course, exceptions, but for most people finding clothing that they'll look worse in than if they were naked requires exceptional anti-talent.
Anyway, point is, there's nothing wrong with nakedness, and any traumatizing impact it might have (in most cases it doesn't) comes from it's sexual connotations, which are pretty pointless. Once you get over this, it's nothing bad or sinful in seeing other people naked, nor being seen naked yourself. Nudity should not be criminalized like it is now.
