A common mistake that most beginning hentai artists make is in thinking that sense their characters are not anime, that they will not be moving. In point of fact there are probably more complicated movements in hentai mangas than in your average general animated cartoon. This is because of the emphases on sex and sexual encounters in all hentai materials. The artists are forced to convey as sense of motion while their characters are having sex with not only each other but with an assortment of creatures both benign and demonic. When a twenty tentacle demon attempts to ravish an innocent women, the reader must be made to somehow ‘feel’ the tentacles thrust out of the demon and then proceed to hold and impale her on his penis like extensions.
The first thing an artist learns is the general anatomy of the human body. Simple arm rotation is probably the most difficult thing to get right. If you get this right it adds a sense of realism to your character. Anatomy teaches you that the muscles that move the arm are anchored in the shoulder so that when the arm moves, the shoulder must move with it.
Unlike normal mangas, hentai characters perform a great deal of pelvic thrusting and for the females the physics of the human breast are most important. Nothing is less believable than a female torso thrusting back and forth while the breasts stay in a static position during the entire process. For males, the movement of the penis as it enters a female vagina is critical. The reader should get a sense of penetration not a simple picture of the penis outside then the next show it fully within the female. When an artist uses his skill to convey moment correctly it almost makes his characters come alive.