Manga comics are read by children and adults. Popular children's manga are often made into animated films and television programs. Recently, manga and animated films based on computer game characters, as well as spin-off character goods, have become a big business. One example is the Pocket Monster series, said to have generated a one-trillion-yen market all of its own. There are even manga museums, which are in places helping to rejuvenate moribund communities.
An average of 1.6 billion manga are published every year for total annual sales of around 600 billion yen. Compared to the total annual sales of all non-manga magazines and books, at 2.5 trillion yen, one can see that manga account for roughly one fourth of all publications in Japan. Manga magazines total 350 billion yen in annual sales and manga books, 250 million yen. Manga are usually compilations of stories previously serialized in manga magazines. Manga are seldom originally published in book form. An estimated total of around 270 types of manga magazine are published annually, ranging from weekly and biweekly issues to monthly magazines, but no one knows the exact number. More than 10 magazines are said to have circulations exceeding one million. Manga magazines are generally targeted at different age groups, from young boys and girls to adults. Manga themes have great diversity, ranging from sports and love stories to gags and satires, history, politics, and economics.
Manga sales have been declining in recent years. The most popular boys' weekly manga magazines, such as Kodansha's Magajin and Shogakukan's Jump, which used to have circulations exceeding six million, have dropped to barely four million. Computer games, the Internet, cell phones, and the growing diversity of interests and hobbies, are considered to be some of the causes for the waning popularity of manga. Others point to the proliferation of stores for used books (see section on recycle shops) and manga kissa ("manga coffee shops") as contributing to the downward trend in manga sales. Manga kissa are like libraries where, for a small fee, one can read manga while having some coffee or tea. A typical manga kissa charges a base fee of 400 to 500 yen per hour with surcharges for each additional hour. Customers can choose from a stock of 20,000 to 30,000 manga in these shops. There are more than 300 manga kissa in Tokyo alone.