Shōnen manga is typically characterized by high-action, often humorous plots featuring male protagonists. The camaraderie between boys or men on sports teams, fighting squads and the like is often emphasized. Main characters may also feature an ongoing desire to better themselves.
Such manga often portray challenges to the protagonist's abilities, skills, and maturity, stressing self-perfection, austere self-discipline, sacrifice in the cause of duty, and honorable service to society, community, family, and friends.
None of these listed characteristics are a requirement, as seen in shōnen manga like Yotsuba&!, which features a female lead and almost no fan service or action; what most defines whether or not a series is shōnen are things like the magazine it is serialized in. After the arrest and trial of serial killer Tsutomu Miyazaki, depictions of violence and sexual matters became more highly regulated in manga in general, but especially in shōnen manga. The art style of shōnen is generally less "flowery" than that of shōjo manga, although this varies greatly from artist to artist, and some artists draw both shōnen and shōjo manga.
Akira Toriyama's Dragon Ball (1984–1995) is credited with setting the trend of popular shōnen manga from the 1980s onward, with manga critic Jason Thompson in 2011 calling it "by far the most influential shōnen manga of the last 30 years." Many currently successful shōnen authors such as Eiichiro Oda, Masashi Kishimoto, Tite Kubo, Hiro Mashima and Kentaro Yabuki cite him and Dragon Ball as an influence on their own now popular works.
Manga has been said to have existed since the eighteenth century, but originally did not target a specific gender or age group. By 1905, however, a boom in publishing manga magazines occurred, and began targeting genders as evidenced by their names, such as Shōnen Sekai, Shōjo Sekai, and Shōnen Pakku (a kodomo manga magazine). Shōnen Sekai was one of the first shōnen manga magazines, and was published from 1895 to 1914.
The post-World War II occupation of Japan had a profound impact on its culture during the 1950s and beyond (see culture of Post-occupation Japan), including on manga. Modern manga developed during this period, including the modern format of shōnen manga we experience today, of which boys and young men were among the earliest readers. During this time, Shōnen manga focused on topics thought to interest the archetypical boy: sci-tech subjects like robots and space travel, and heroic action-adventure. Osamu Tezuka, creator of Astro Boy is said to have played an influential role in manga during this period. Between 1950 and 1969, an increasingly large readership for manga emerged in Japan with the solidification of its two main marketing genres, shōnen manga aimed at boys and shōjo manga aimed at girls.