The history of eromanga is not a single, straight line. There is influence from the “outside,” even as eromanga influence manga in general, which then feeds back into and is reflected in eromanga. Now is not the time of so-called “third-rate gekiga,” which are much more associated with the 1970s, but those works live on. Lolicon manga is no longer mainstream, but as a subgenre it still has a stable fanbase. I have no intention of insisting that I have written the one true history of eromanga. While grasping the large trends from a macro perspective, I zoom in to a micro perspective as necessary. I also have no intention of telling grand stories about epochmaking artists and works, for example how Moriyama Tō's The Sexual Education of a Good Kid (Yoi ko no seikyōiku, published by Shōbunkan in 1985) redrew the map of eromanga in Japan. Certainly Moriyama Tō (aka Yamamoto Naoki) is an important artist in the history of contemporary manga, and his influence is perhaps on par with Tezuka Osamu and Ōtomo Katsuhiro, but that does not mean that eromanga artists all belong to his school. The history of eromanga is multilayered. Even if one style usurps another in the mainstream, the unseated style is not eradicated. Reduced in scale, the style remains. In other words, the number of styles increases as long as history continues. Old styles experience new booms, and styles that resemble old ones appear as something new. This is also the case with the sex appearing in eromanga.

In this book, I focus on contemporary eromanga, which is dominated by what is called the otaku or bishōjo style. This style first appeared in the early 1980s, and I would like to observe closely the confluences that contributed to it then and since. Just about everything flows into contemporary eromanga: imagination and imitation, tradition and insurrection, general trends and divergences, interruption and discovery. Unimaginable strata have built up beneath the surface of contemporary eromanga. It is no exaggeration to say that the history of eromanga began when mankind drew antelope and buffalo on cave walls by the light of burning tallow: the pleasure of drawing; the pleasure of expressing; the pleasure of showing; the pleasure of conveying excitement, awe and Eros to others (Hogben 1949). That said, we would probably never reach contemporary eromanga if we started from the Cave of Altamira.