I haven't written on Japanese manga (comics) for some time. I would just like to point out that one of the neat things about manga, especially action adventure stories like "One Piece" and "Naruto," is that they capture very specific moments akin to Japanese sensibility. Every now and again you get a very distinct "feeling" of Japanese culture, or tradition, through an image. The culmination of input, over time, leads one to have some sense of how the Japanese see the world -and how they depict it in their art. When one reads as much manga as I do, you often will find that you develop a sort of "sense" about Japan. Granted it is less than a sliver of a notion of what the real Japan is like, reading manga does give you some insight into how Japanese people think and sometimes act. Like any culture, their stories and art represents various facets of their culture.
When I first went to Japan I had certain "notions" of how things would be from the comics and animation I had seen. To my pleasure, I was more often wrong than right about my assumptions, and I found the experience quite gratifying and educational. Yet in no way did my view of Japan change too drastically as for me not to love every moment of it. It's really something which happens when you go into any culture. Most Japanese think America is extremely violent like in the movies and television -many outsiders think that about America and the U.S., but that's not an accurate picture of this country. American's live quite peacefully. I found this to be the same of Japan also. My ideas were only enlgightened to see the "bigger picture." I guess what I'm saying is, enjoying manga and other Japanese cultural elements is healthy and a good way to learn about the country, but if you really want to learn about the 'real' Japan, go experience it first hand!