Manga is an interesting concept in Japan. So much more than a simple comic it covers genres from romance to science fiction to horror to graphic detail that will make your great auntie blush. It's also a massive, multi-billion dollar industry that represents an estimated 20%+ of the publishing market here. Manga are highly stylised pieces of contemporary art in their own right many of which become collectors items valued by child and adult alike.
The industry was created in the late 19th century though grew rapidly in the austere post war years when there was little else to entertain the masses. One key difference to the western style comic though is the audience. You are as likely to see a business man on a train engrossed in a story as you are to find a teenager with their nose in the book in a convenience store on a Friday evening.
We once commissioned a manga for from a number of top Japanese manga artists to celebrate the 2002 World Cup held in Japan and Korea. Forgetting to brief in detail that the intended audience included many from overseas the artwork was beautiful, story lines strong and the warning stickers we had to put on each copy, bright red and very clear.