Story manga (Japanese: ストーリー漫画) is the dominant form of comics in Japan whose themes are overtly dramatic (akin to film, hence the name "story" manga) which utilise time-synchronized sequences, size and layout of strips in a double-page spread, along with the viewing speed of the reader to simulate dynamism, similar to cinema storyboards. The time-control technique of story manga means that frames are set out chronologically, linked by motion lines or onomatopoeia with little or no narrative text. It is generally accepted that Osamu Tezuka pioneered story manga after World War II, while recent research suggest that technique of cinematic presentation has been used much earlier. In contrast, the comics prevalent in America are characterized by more densely drawn color illustration accompanied by a larger amount of text. This type of comic, similar to story books, requires readers to stop at each frame for a significantly longer time and "read". Moreover, the majority themes of American comics were limited until very recently to the superhero genre, whereas story manga tend to be more diverse in genre and theme.
Komawari literally means frame splitting/allocation. Because the Japanese language is written from top to bottom, right to left, frames can be viewed more easily if they zigzag from top to bottom and right to left. This arrangement allowed the reader to view rather than read the page. Also to compensate for the increased viewing speed between frames, Tezuka, who is credited as the founder of story manga, conveyed information more through pictures rather than through text. For this purpose, he eliminated narrative text almost entirely by introducing more sequences of strips to convey the shift in events or by using side characters' dialogue to indicate the story. To maximize information through pictures, he utilized many symbols and onomatopoeia, for example, in Japanese manga, the "#" symbol on someone's forehead (frown) means that person is cross. As this technique massively increased the number of strips needed to convey each scene of story, caricatured line drawing similar to Disney cartoons became widely popular among Japanese comics.
Until very recently, the establishment of the time-control system had been credited to the work of Osamu Tezuka in the period immediately following World War II. However, recent academic research show that a prototype version of story manga can be seen in much earlier works such as Krazy Kat (although that was still a one-panel comic strip) and Sho-chan no Bouken (正チャンの冒険?, "Sho-chan's Adventure"), published in 1923 which has 52 frames over 13 pages for each story using cinematic viewing angles such as zooming out or close ups. This pre-dates The Adventures of Tintin, first published in 1929, and "Superman" from 1933.
However, it is accepted Tezuka made a concerted effort to move manga's storytelling from children's fantasy stories to more mature cinematic stories. He often introduced tragic plot elements (such as the death of main characters) and characters with complex backgrounds and motives. His manga stories ranged from medieval-themed action horror (Dororo), medical drama (Blackjack) or fantasy historical epic (Phoenix) to modern adaptation of classic literature (Faust). While it is not longer accepted that Tezuka invented the cinematic technique, there is still wide consensus that he is the founder of "story (based) manga".
Tezuka also made a number of innovations in cinematic technique, most notably one being much freer and therefore more dynamic use of frame size and layout as well as liberal use of onomatopoeia and symbols to convey information without use of text.
Gekiga (劇画) is Japanese for "dramatic pictures." The term was used by Japanese cartoonists who wanted to differentiate their works from the mainstream story manga popularised by Tezuka.
Story manga became vastly popular in Japan and became the main revenue source of major print publishers, often surpassing the combined revenue of book and magazine. Many popular manga started to be serialised weekly. As a result of this rapid weekly production cycle, detailed drawing in colour became impracticable and Disney-like caricatured faces in black-and-white became the main drawing style of manga.
However, by the late 1960s and early 1970s the children who grew up reading manga wanted something aimed at older audiences and gekiga provided for that niche. These "dramatic pictures" emerged not from the mainstream manga publications in Tokyo headed by Tezuka but from the lending libraries based out of Osaka. While the weekly production cycle of manga necessitated Disney-like line drawing, the lending library industry allowed gekiga cartoonists to spend more time and resources on drawing and writing. As a result, gekiga is characterised by more dense, detailed, and realistic drawing and is much more artistic and experimental. The gekiga artists eliminated caricatured drawing and criticised Tezuka's story manga for still containing comedic elements aimed at children. The growing popularity of gekiga, in turn, influenced Tezuka and his followers who began to draw gekiga-themed cartoons after the 1970s.
As the distinction between manga and gekiga begun to blur, some gekiga artists began to strive for mainstream success. The main bottleneck of gekiga in mainstream production was the highly intensive and time constrained weekly production cycle of shonen-shi. Takao Saito, of Golgo 13 fame, is credited as breaking this bottleneck by introducing the factory-style production method, where each "worker" specialises in one aspect of manga production, such as writing, framing, lining, toning, tracing and backgrounds. Takao even went as far as creating Saito Production Ltd, which managed and directly published his team's work, and declared that he no longer directly involved himself in drawing. This mode of production was later adopted universally by all professional cartoonists.
Another consequence of this mode of production is authorship of manga. In Japan, authorship of manga is not given to the person who actually drew the picture but instead given to someone who drew up the komawari (literally "frame division"), that is someone who decided size and positioning of strips for pictures and dialogue, much akin to the director of a film. In professional manga production, which often has to produce chapters every week, the majority of drawings are almost always done by a number of assistants who specialise in specific fields such as background, inking/tracing or placing toner.
By the 1980s, as the lending library industry shrunk and disappeared, gekiga become a genre within story manga, and the word manga in Japan, by default, began to mean story manga. One of the signature gekiga-style story manga which became well known globally is Akira. Gekiga is now seen by many as the continuation of movement started by Tezuka, and is incorporated as a style within manga.