In 2002, the Japanese poured nearly 500 billion yen into comic books. Nearly two billion volumes of comics and comic magazines were published, comprising just shy of 40% of the publishing market. Take a look around Japan, and you will see that this country is saturated with manga.

Train station kiosks and bookstore shelves are piled high with comics and comic magazines. There are even coffee shops just for reading manga. Adults on trains are mesmerized by comics.

Why is highly literate Japan so taken with manga? Are these manga really as violent and sexual as we are often led to believe? In an effort to unearth the truth, I picked the brains of a few people.

"Japanese manga are not just for kids. They have diversified while developing to meet the needs of consumers," said Akita Takahiro, Director of the Japan Society for Studies in Cartoon and Comics.

Currently 281 varieties of comic magazines — transcending gender and generation — are published. Manga themes span the gamut from the romantic to the culinary, and include horror, historical and economic titles, as well. There appears to be plenty of manga material for adults to enjoy.

"I have read manga since I was a kid," a recently retired 60-year-old friend told me.

"I used to read them in the train when I was commuting to work. They helped me forget about the stress of work."

"Japan is the first nation to accord comic books the same social status as novels and films," said U.S.-based manga authority Frederik Schodt.

"In Japan, manga is not a genre, but an independent medium for expression," said Minamihata Toshiharu, an advisor to Shogakukan, a leading manga publisher.

Manga, like novels or films, possess the power to tell a story, he says. If the human story has tears, laughter, anger and more, it is only natural that some works will contain expressions of sex and violence, Minamihata contends.

In Japan, storytelling through pictures has a long history. The scrolls of chojugiga, or humorous pictures of animals and birds, are believed to have been sketched around the 12th century.

Many years later — and with a bit of influence from the West — what has become today's mainstream, story-type manga began to appear after World War II. The next 50 years witnessed a dramatic evolution of the medium, with the manga market hitting its peak around 1995.

The popularity of manga in Japan now appears to be flagging, according to Sasaki Toshiharu of the Research Institute for Publications. Instead, more publishers appear to be looking to launch forays into overseas markets.

Manga may start appearing on the shelves in a shop near you soon. Then we will see if the charm of these unique stories can win the hearts of people everywhere.