Seinen

Seinen manga (青年漫画?) is a subset of manga that is generally targeted at an 18–30 year old male audience, but the audience can be much older with some comics aimed at businessmen well into their 40s. It has a wide variety of art styles and more variation in subject matter, ranging from the avant-garde to the pornographic. The female equivalent to seinen manga is josei manga. In Japanese, the word Seinen means "young man" or "young men" and is not suggestive of sexual matters. Examples include: 20th Century Boys, Berserk, Elfen Lied, and Hellsing. A common way to tell if a manga is seinen is by looking at whether or not furigana is used over the original kanji text: if there are furigana on all kanji, the title is generally aimed at a younger audience. The title of the magazine it was published in is also an important indicator. Usually Japanese manga magazines with the word "young" in the title (Young Jump for instance) are seinen. Other popular seinen manga magazines include Ultra Jump, Afternoon, and Big Comic. (text from Wikipedia)