In the past, it was the parents and not the readers who bought manga. So children were made to give up manga by the time they entered junior high school due to their parents' wishes. Parents told children to stop reading manga. The situation was similar in America 10 years ago. Manga was something that parents bought for their children, so children usually stopped reading manga by the time they went to junior high school. It is said that the population of manga readers over 20 years of age in the entire United States was about 150,000 at that time. In this way, an upper limit was set in the manga market as readership was artificially restricted.

 In Japan, readers became buyers due to the rental library system. Urban children were able to use rental libraries and borrow 1 book for about 5 yen. The main product in rental libraries changed from popular magazines and novels to manga books around 1955. Children could afford to rent and read mangas from rental libraries using their pocket money since they were widely circulated and could be borrowed cheaply. Incidentally, it was interesting to see when I went to Vietnam recently that two thirds of manga readers there also used rental libraries. Rental libraries constituted the main market in South Korea too during the manga boom in the late 1970s.

 Children's pocket money increased during the period of high economic growth. The regular price of Shonen Sunday and Shonen Magazine first published in 1959 was 30 yen per copy. They were published 4 times per month so it amounted to 120 yen per month. Since students in 5^th and 6^th year of primary school were given pocket money of around 100 yen and many did not have any pocket money at all, it was rather difficult for them to buy their own copies. The sales went up around 1962 as the children's pocket money increased and they were gradually able to buy at least one and exchange it with their friends even though they could not buy both.

 In the meanwhile, the publishing companies would be in trouble if the children in the upper grades of primary schools stopped reading manga once they went to junior high schools. So they started weekly boys' magazines targeting children of upper grades of primary schools and junior high schools. The first edition of the weekly girls' magazine Margaret was distributed free to 6^th grade girls of main primary schools all over the country. The entire company put its effort into getting 6^th grade girls to read the magazine.

 Then from around 1962, pages of manga rapidly began to take over pages of writing in magazines. Let us take a look at the development of children born in 1947 in terms of development of manga. Weekly boys' magazines appeared in 1959 when these children were 12 years old, around the time they were 6^th graders in primary school or 1^st graders in junior high school. Weekly girls' magazines appeared when they were 15 years old, around the time they were 3^rd graders in junior high school or 1^st graders in high school. Television animation 'Tetsuwan Atomu' began when they were 16 years old, and sales of Weekly Shonen Magazine reached over 1,000,000 when they were 19 years old. This is significant because these children would have had to stop reading manga when they entered junior high school if their parents had bought manga for them, but they could go on buying manga themselves even until they reached university age. Thus the magazines also had to change the contents of the manga to satisfy the readers. On the one hand, there were indeed adult mangas which were sexually attractive and contained social critique. But at the same time, they had to produce mangas which were not like that and contained action. 'Kyojin no Hoshi' and 'Ashita no Jo' appeared under these circumstances.

 Then young men's magazines such as Manga Action, Young Magazine, Precomic and Big Comic appeared when these people were 21 years old. The publishers realized that it was no longer possible to attract these people with boys' magazines so there was a boom in publication of young men's magazines.

 On the other hand, the publication numbers of boys' magazines dropped considerably in 1971. The sales of Weekly Shonen Magazine which went up to 1,500,000 at one point suddenly fell by half to about 700,000. It is said that the reason for this was because the mangas were drawn for university students and children found the content too difficult to understand. This is similar to the case of Shonen Jump which I mentioned at the beginning.

 Then when these people were 30 years old, there was a social uproar about salary men reading mangas. By around this time, magazines for children such as Shonen Jump and Shonen Champion became popular, and a market system was gradually formed in which readers who started off with children's magazines shifted to young men's magazines at one point.

 A notable event in 1977 was the first publication of Young Jump. The baby boomers were already in their thirties, and since the readership age increased as the magazines catered for their needs, there was a gap between them and the generation who had grown out of reading weekly boys' magazines. Young Jump was published in 1977 and Young Magazine in 1978, targeting the generation in between and filling the gap. Publication of Big Comic Spirits followed. Thus the tendency continued where each publishing company introduced new magazines to fill the gap created between young readers and older ones as the readership age increased.

 In 1985, there was a sudden increase of publication of ladies' comics. By then the baby boomers had reached their thirties so these comics targeted women, housewives and female office workers. On the other hand, the number of manga magazine publications gradually began to decrease from around 1989. The same people were now 42 years old, so perhaps disposable income decreased due to educational expenses for children and housing mortgages.

 By around the 1990s, the marketing strategy of publishing companies changed. Since it would be endless to pursue the baby boomers, the target was shifted to the children of this generation, the so-called baby boomer juniors or 'ichigo sedai' (strawberry generation). They set up one market for junior high school students and high school students, one for high-school students and university students, and one for people in their twenties and thirties. Age groups above these were considered negligible.

 Manga publishing companies had to produce manga in accordance with the readers' ageing process as their marketing strategy tried to hang on to the readers. I think this is one of the main reasons why the Japanese manga market developed in a particular way. It was very easy to include new aspects because the market was multi-layered. Another important factor was the formation of a system in which the readers became the buyers. Whereas they would have stopped reading manga if their parents had continued to buy them, the children continued to read manga even when they entered junior high school, high school and university, and even when they became salary men.

　

 It is regrettable that fewer children read manga as the publishing companies have paid too much attention to producing works to match the development of the baby boomer generation and have pushed up the readership age. The political fiction manga 'Hikaru Kaze' (Shining Wind) by Yamakami Tatsuhiko, for example, was a masterpiece even in terms of science fiction, but it was not interesting for primary or junior high school children.

 Children have stopped reading manga because there are no longer many mangas that they want to read. As we can see by looking at the distribution of readers of Shonen Jump, what is most important for the manga market is to make sure that there is an influx of children starting to read manga, and attention must be paid to how this number decreases with increase of age. In most cases, children start reading manga from about the age of 9 and the core readership is aged between 12 and 19. It is best if the number of readers decrease gradually with age. However, if the publishers think that since their manga is read by university students, they will cater for university students' tastes, the children will not find the mangas interesting. They forget the most important point that children must start reading manga. After all, 'Doremon' is best for children.

 It is not just the baby boomers who sustain the manga market. I explained the situation using the baby boomers as an example because it is the easiest way to elucidate the expansion of the market. The situation can be best understood by visualizing an inflating balloon. You can grasp the state of market expansion if you imagine that children are supplied from the middle, like air being pumped into a balloon expanding outwards. So as the children grow older, the manga market expands like an inflating balloon.

 Therefore, readers increase when there is a wide range in readership age. The market shrinks if there is only one generation reading manga. For example, the readers of Shonen Champion are aged between 13 and 19 and the market graph looks like a very high sharply peaked mountain. The publication numbers are small in this case. In contrast, Shonen Jump manages to maintain a publication number of 3,000,000 because the readers started reading the magazine as children and the number of readership decreases gradually with increase of age. Today, the baby boomers are probably not reading much manga. The publication number of Big Comic is 800,000, so the readership is probably around that figure.

　

 I think we should also take into account the fact that value standards changed due to defeat in the war. The collapse of existing values was no doubt behind the fact that major publishing companies such as Shogakukan took on authors of picture story shows which they had not dealt with previously, and magazines accepted authors of akahon and rental manga.

 Another important factor is the sudden change in social conditions of children. Children's pocket money increased due to high economic growth. Parents let the children grow up freely instead of being with them all the time. Many children were given keys to the house and many started going to cramming schools. Thus children were able to have their own time. This led to children leading the consumer market.

 Manga overcame the generation barrier as readers became buyers. Different kinds of genre were introduced which were not dealt with previously. For example, manga started to convey messages to teenagers. This is one of the reasons why Japanese manga attracts readers all over the world. It is said that Japanese girls' manga has become a great hit in Germany because there was no children's literature that teenage girls could relate to until then. There are many boys and girls in other countries too who want to sympathize with the psychological development of the characters, but there are not many children's books which they can relate to. It is often pointed out that otakus exist abroad as well, however we should keep in mind that the market is sustained not by them but by children who relate to 'Inu Yasha' and 'Goku'. These are children who relate to the world of Doraemon and Nobita. If we focus too much on the fact that Japanese otaku culture is accepted worldwide, I think that the boom will just become a temporary one.

 Lastly, let me mention some serious future problems. The range of manga readership expanded from children to adults as the baby boomers pushed up the age limit. The oldest people who read Shonen Jump were in their forties when the publication number of the magazine reached 6,000,000. But can the age limit be pushed further upwards when the baby boomers reach retirement age? We can say that there is a limit in maintaining market expansion by increasing the readership age. The publication number of Big Comic Original is 1,000,000. In terms of distribution of readership, the largest is the 35 to 39 year old group which constitutes one quarter. The next largest is the 40 to 44 year old group which constitutes around 23%, followed by 7% of readers over 50 years old. There are not many readers below the age of 35. There will be a problem if these people start saying, 'Maybe I should stop reading manga since I'm now 60.' I hope they will say, 'I'm going to read manga' even after their retirement.