The term "eshi," written as "絵師" in Japanese, refers to those who vocationally paint original pictures for ukiyo-e (Japanese colored woodblock prints in the Edo period).
In short, they are Japanese-style painters. This term is also written as "画師."
In this term's new usage which started to be used from the end of the 1990s, it refers to the painters or the illustrators who paint or draw pictures mainly classified as Japanese cartoons, animated cartoons, and video game style animations.
Eshi as a Japanese painting and ukiyo-e painter
Japanese people did not use to have the concept of a painter as an artist in and before the Edo period, but they thought of a painting specialist as a technician or a craftsman who had excellent skills of painting. This is why this term uses the Chinese character "師" (pronounced as shi), which represents a skilled person.
Also, an ukiyo-e printing involves a number of craftsmen who utilize the technique of woodblock printing to make printing blocks based on the original picture, and this makes ukiyo-e mass-produced. Accordingly, eshi also had a function of what people of today call key animators or lead animators in animated cartoons and video games.
In the Edo period, eshi were classified as 'goyo-eshi' (an official painter) or 'machi-eshi' (a town painter), and the Kano and the Tosa schools were famous among the goyo-eshi groups, and the Maruyama and the Shijo schools were well-known among the machi-eshi groups.
In recent years, illustrators in the world of subcultures are sometimes also called eshi. Those who enjoy their work mainly use this word as a term of respect, and using the Chinese character "師" which represents a skilled person also implies their attitude of respect, just like the case of Japanese-style painters as described above.
For this reason painters hardly call themselves eshi, but they often call themselves 'ekaki' (a painter) or 'eshi no naka no hito' (literally means "a person inside eshi") instead.
People sometimes think illustrations (or graphics) are the more important element, rather than the stories in cartoons, animated cartoons, and video games.
Therefore cartoonists and lead animators for animated cartoons and video games who can paint or draw beautiful pictures have gradually gained steady fans who regard them as artists, and their one-of-a-kind illustrations and illustration collection books are now distributed in large quantities.
Also, many ordinary people paint or draw and publish derivative works (such as cartoons) and their original illustrations, as part of their hobbies or club activities.
The spread of the Internet enabled them to publish their work to the whole world through websites in simple steps.
Consequently, there have been many cases of a so-called opposite phenomenon whereby some amateurs are appreciated and engaged as video game lead animators, cartoonists, or as illustrators, according to the reality that they have obtained a large number of fans through websites.
Their production activities are totally different from the activities of traditional 'artists.'
In other words, unlike traditional artists' works, their original pictures (their most primary pictures) are made with computer graphics, not on paper or canvases, and this allows them to make an infinite number of complete duplications of their originals, which are distributed on the Internet (occasionally regardless of the artist's intention).
In addition, their values in regard to their works are backed up by their common subculture, which is generally called 'otaku' (geek) culture, instead of the traditional artistry and commercialism. As a consequence their world has had nothing to do with the art industry which belongs to the high culture (thus people do not think of Takashi MURAKAMI as an 'eshi').
The term 'eshi' or more specifically 'moe eshi' (a painter who draws pictures of cute, young female characters to whom one forms a strong attachment) is now widely used to refer to painters whose activities are beyond the range of traditional painters or illustrators.