A Statistical Analysis of History of Japanese Light Novels

In recent years, cool Japan anime, video games and manga have been recognized as important export-oriented merchandise in Japan. Another recent Japanese genre is light novels. Light novels are one of the genres of novels and construct a part of recent Japanese pop culture. In Japan recently, the anime, manga and live-action films have been adapted from the original light novels. Light novels were chiefly read by high and junior-high school student previously, but the range of the readers has been expanding widely in recent years. However, light novels have not been statistically studied yet. In the present study, 533 titles of popular light novels published in 2004-2020 were investigated to clarify the trends in the genre.Numbers were counted for each of 129 items, data of published year, publisher, label, platform first appeared on, length of time from the first publication to the release of the anime adaptation, length of time from the first publication to the manga adaptation and so on for each year. And a 17 x 129 cross-tabulation table was constructed. Then it was analyzed by correspondence analysis and cluster analysis.The results of the correspondence analysis showed a three-dimensional solution with a cumulative contribution ratio of 64 %. Each year was plotted on the three-dimensional space, then cluster analysis was performed on the plots with Ward’s method. The results of the cluster analysis showed that the plots could be divided into four periods; 2004-005, 2006-2015, 2016-2017 and 2018-2020.The results showed that KADOKAWA’s labels were popular between 2004 and 2014, but the other publishers’ labels which collect novels appearing in individuals’ private home pages or posted on web-sites became popular in recent years. The most important part of the business strategy of light novels is mass-production, which means a large number of works and writers are needed. As such, it stands to reason that internet novel submission sites have become an important source for publishers.The results also showed that it only took one or two years to produce anime for many titles between 2006 and 2014, but in recent years, the period of time has increased to four years and the number of cases where no anime was produced has also increased. Additionally, manga based on the light novels tends to be published within one year. This suggests that the center of the multimedia strategy of light novels has shifted from anime to manga. Since the mid-2010s, tablet devices and e-comics applications have rapidly developed. This has enabled publishers to rapidly produce and publish manga based on the original light novels. Moreover, it now takes longer to produce anime, because the quality of frames and productions costs have increased. Therefore, anime studios tend to select an original work of light novel carefully, observing the sales of the e-manga adaptation.