The demographic compliment to josei is seinen (SAY-nen) or men’s manga.
Seinen skews to a more mature demographic then shonen but generally retains the more youthful genre’s emphasis on adventure. In some cases it can be difficult to discern what makes a manga seinen rather then josei as the topics addressed and the way they are handled seem appropriate to either demographic. The gender of the mangaka is not a good genre indicator as there are many examples of women who create seinen narratives and men who write josei (thought there seem to be fewer). The differentiation seems to come down to the art style and if the manga is published in a seinen or josei weekly publication.
It’s often easier for a North American audience to grasp the difference between shonen/seinen then shojo/josei because the shonen/seinen duality generally fits Western censorship templates. Seinen has more graphic depictions of sex and violence then it’s youth-targeted counterpart. However, it would be misled to think that even the more explicit examples of seinen can be dismissed as prurient and exploitative. There is also a lot of textual complexity and themes intended to appeal to older readers (not just men).
The seinen genre strongly influenced North American comic artists in the 1980s and lead to the first wave of the self-reflective and genuinely artful “super hero” redux. Much of durability of Batman’s and Wolverine’s cultural credibility is owed to seinen comics.
Two seinen titles that are in the top five “Top Viewed” titles on the fansub site One Manga are Bitter Virgin and Gantz. Taken together, these two titles are a good illustration of diversity of seinen.
Bitter Virgin by Kei Kusunoki is about a young man who inadvertently finds out about the troubled past of one of his female classmates. The story is seinen in the way it appeals to the protagonist’s (and the reader’s) sympathetic and protective response to the shy, unfailingly adorable and fragile young woman. However, the story reaches a surprising and intense narrative peak with a heartbreaking sub plot based directly on the manga-ka’s (artists) experience with the stillbirth of her first child. (Thanks to Solaris-SVU for all their work on the Bitter Virgin fansub.)
Gantz by Oko Hiroya has recently been optioned by DarkHorse and it is therefore harder to find scans online. Gantz embodies everything that parents are afraid manga is about. It has an interesting premise, good plot development and the art and page design are creative and compelling. It also begins with the graphically rendered decapitation of the two main protagonists. (Sorry, if you can’t imagine where the story will go from there, you’ll have to read it yourself to find out.) Gantz is nightmarishly violent and there are lots of depictions of enormous breasts.
Images: Gantz v.2 (cover image) by Oko Hiroya, character art from Bitter Virgin by Kei Kusunoki, panel from Gantz by Oko Hiroya