Originally Posted by the wiki

H anime is an artistic expression of pornography in Japan. As opposed to photographic erotica, they allow full use of the imagination as well as scenes that run counter to accepted society and culture. Elements of sexual fantasy are represented in ways that would be impossible to film.
This is not without precedent in Japan. During the Edo Period, which was the heyday of ukiyo-e wood-block prints, ukiyo-e had a pornographic variant, called shunga, which also had scenes that were sometimes surreal.
Each culture will have a different understanding about the line between pornographic content and mainstream works. It is important to understand ways that the Japanese line might be different from that in other cultures. Children's anime can depict nude characters, for example in Sailor Moon it is implied that the girls are nude during their transformation, and in Digimon Frontier and Digimon Tamers, Zoe, Jenrya, Takato, and Ruki are nude during spirit evolution sequences and bio-mergance, respectively. Many artists add nudity as fanservice. On the other hand, H material tends to use explicit erotic content.
As a form of expressing sexual fantasy, depictions can include those which are unacceptable in society, or run counter to social norms. Such fantasies can be depicted in the extreme, often demonstrating subconscious desires or purely carnal motivations. This contrast between accepted—and in some cases legal—behavior and primal sexuality is a primary motivation for many works of pornography, and H art is no exception.
This form of Japanese culture acquired some popularity in the West, thanks, to a large extent, to the Internet. Although there have been many pornographic comic books and animations produced in the West, they never were as popular as H manga is today. Comic book artists who focus on provocative female figures often use their talent for mainstream comic companies rather than adult works, and may fear ridicule for working on niche adult titles that are not as widespread, compared to Japan where a large group of artistic talent draws pornography.
In comparison to other forms of pornography, H art often portrays women as regular people in society who end up in some kind of sexual encounter, and are often aroused by the encounter to the point of no return. Characters may be portrayed as shy or have no conscious thoughts about sex, until placed in a situation where they are stimulated and aroused. While there is a common theme of a male stranger convincing a woman to become aroused physically by her own body and whatever the male desires, there are also depictions of consensual sex between couples, as well as assertive women who initiate sex.
Often, H artists try to portray situations in the most extreme manner possible, in order to break the boundaries of the viewer's comfort zone. This results in artists competing to show successively more excessive situations over time. An example would include bukkake and group sex, which demonstrates extreme sex that isn't usually performed by the average person. Other forms of demonstrating extreme sexual activity include bondage, tentacles, or other fetishes. Some artists may prefer to do the opposite, and focus on lighter titillation and nudity, or on character relationships and story.

Originally Posted by Joe

It leaves a lot to your mind....and besides it sometimes a lot prettier than the real thing.....some may know what im talking about! (ewww)
I for one like Hentai....and the real thing....but its normal for most people to dislike it....but that really dosnt make anyone weird if they do like it!
Maybe if you actually spent some time with it yourself...youd understand .....^_^

- Japan is AWSOME!