Maeda Hachibei is unlike most guys, who lust after gorgeous girls. This pervert lusts after their discrete parts, instead. When he moves to Tokyo to attend school, he finds himself living in a dormitory with five girls, each of which possesses one of the ideal physical features he desires: gorgeous blue eyes, bullet-train breasts, a deep dulcet voice, straight “anime-esque” legs, or a waistline shaped like fine Japanese pottery. How can he manage to keep his wits when surrounded by these women? If you think this sounds like a Love Hina clone, you wouldn’t be entirely incorrect… but Hachibei isn’t Keitaro.

Includes a oneshot in Vol.12: "The Boy Who Heard Too Much".

Touma Outa wakes up from a bad dream one morning and when he sees his reflection, there are horns growing out of his head. Suddenly, he is pounded in the head by a cute, hammer-carrying knight from the demon world. The horns shrink, but he is not off the hook yet, for the little knight, Pukateriosu, is there to prevent him from transforming completely into the Demon King whose soul has entered Outa's body. The PukaPuka hammer can return him to normal but it takes time to charge. In the meanwhile, Outa must try not to think worldly thoughts or be kissed, but it's easier said than done with his crush Shirayuki Himeka, the little demon Garbelion, and even Pukateriosu around...

Strippers try to stop a zombie infestation.

Maico is a charming young woman who also happens to be an android. Her creator built her to revitalize the flagging ratings for her radio station, as well as to probe the intricacies and weaknesses of the male libido. Maico quickly becomes entangled in a very human love triangle, not to mention the scandal and intrigue surrounding the station, its competitors, and the hordes of adoring fans that this sexy new personality attracts.

This is a collection of short stories by Suihei Kiki that were serialised in the Seasonal Gangan Powered magazine's 2003 Winter issue all the way to its 2004 Winter issue. Ignoring the tame nature of Suihei Kiki's debut work "Mahou Shoujo Rukana", Suihei's "Mika ni Harassment" short stories are extremely ecchi in nature for a manga serialised in a shounen magazine aimed towards children. Ecchi to the point that the compilation in March 2005 was jokingly advertised as Square-Enix's first adult manga.

Mika ni Harassment: In the first story, Mika makes a wish on a mirror in order to change the world into one where boys don't have ecchi thoughts when they look at girls. In the second story, Mika's school falls under the control of a misogynic dog who hates high school girls (which includes Mika). Finally, in the third story, Mika raises the ire of six-year-old child genius, Kokoa, who forces Mika to attend kindergarten again.
Kasumi Otoko no Ko: A story about a girl called Kasumi who is a tomboy. One day, Kasumi's friend, Haruna, gives Kasumi a Chinese doll that supposedly houses an ancient Chinese goddess of femininity. Kasumi drops the doll into a ditch, which causes the doll to seek revenge on Kasumi.
Mahou Shoujo Rukana: A story about a boy named Shuuichi, who has a special power that lets him communicate with animals. One day, Shuuichi moves in with a scientist who wants to study Shuuichi's special abilities. Also, the scientist's daughter is a magical girl called Rukana. Though, Rukana breaks many magical girl stereotypes.

Note: The author published sequels in form of hentai Doujinshi.

Mazinger Angels chronicles the adventures of four women who pilot giant robots in the Mazinger vein. The concept is a spoof on the late 70's and early 80's popular TV series Charlie's Angels.

Three of the robots, Aphrodite A, Diana A and Minerva X are from the original Mazinger Z series, while Venus A is from the Great Mazinger series. Their pilots are also traditional characters from Go Nagai's universe, Sayaka Yumi and Jun Hono from Mazinger Z and Great Mazinger respectively, and Hikaru Makiba and Maria Fleed from Grendizer.

The style of the manga highlights the sex appeal of both the characters and the mechas, sometimes similarly to the way Aika's female characters are shown. (taken from wikipedia)

Hirayama, an aspiring manga writer, is thrilled to be chosen as a last minute replacement assistant for a celebrated manga writer he really admires. To his surprise, not only is his boss a woman, but she works semi-nude. In such a distracting environment, Hirayama must find a way to make a good showing of his ability.

From Project Bite Me! Scanlations:

In a world where women are constantly wanting to kill themselves and insult the hard working women that work at Soapland, a single man rises up to stop them! Who is that man? That man with the super masculine form and a body of steel? It's none other than Nikutaikan-K! While he blindly rushes to their aid, maybe his first action should be to find out what is causing these women to want to die in the first place?

Adapted From Neon Genesis Evangelion. A short story in the lives of the young Evangelion pilots. One hot day, Shinji gets into a fight with his apartment-mate Asuka, due to her revealing clothing. Will Shinji be able to figure out how to patch things up with her?

?Onegai Twins? is a cute, incestuous love story between a boy and two girls who are supposedly his long-lost twin sisters. The story follows Maiku, Karen, and Miina. Maiku is a high school boy orphaned at an early age, now living in a house he believes is the house he grew up in. Onegai Twins! is the sequel spin-off to Onegai Teacher!

Keisuke and Makura are childhood friends who grew up together almost like brother and sister. One day, due to a misunderstanding they had, Makura left the house angry until Keisuke's Mom is worried about Makura not coming home yet, thus Keisuke is told to go look for her. Reluctantly, Keisuke went out to find Makura, He ended up at a place they used to go often, the sunflower field. Luckily, Makura was there. Keisuke joined her sitting on the bench and they began to reminiscence. When Keisuke decided that they should head back home, he phoned her mom to say that he found Makura, only to be shocked when her mom told him in panic to head to the hospital. At that same moment, he looked at Makura, who was not standing but floating in the air...

A mysterious command arrives from a "King".
The life-threatening "Game" has now begun for the 32 students of the first year's B Class.
One day, all of the students in Nobuaki's class received their first message from someone calling themselves the "King", in which was written a baffling command.
That first command was very easy. However, the commands began to escalate until a life-threatening game had begun.
Failing to obey the orders leads to death!! Their friendships are being undermined by a bottomless terror!!

Shinjirou's brother is a brilliant scientist whose chosen career is making weird cell phones. Shinjirou has received a gift of his brother's latest product, the Doll-Phone, which is a walking, talking, tiny girl who doubles as a cell phone. But he can't help feeling that a phone like that seems kind of perverted to use...

Rocket Princess was written by Nobuyuki Anzai before he started his work on Flame of Recca.

Basically, we follow Ishibashi Kango through his days as he interacts with a cyborg by the name of Oozora Kohime.

If you liked Flame of Recca, then I'm pretty sure you'll find something to like in this one, too.

From TokyoPop:

After 1000 years of peace, the wolf god Fenris Fenrir has been reborn. She seeks to find the reincarnation of Balder, the most beloved God, as the land of Midgard sinks further into anarchy. They are both key players in the coming of Ragnarok, the time when fate and free-will shall come into conflict as the very nature of the universe is forever redefined.

RilleL:
Based on norse mythology, ragnarök is the term for the end of the world. Christian equivalence would be the last judgement.

The popular Korean MMORPG "Ragnarok Online" was based on this book.

From Tokyopop:
On a world with no women, the surviving men have reintroduced the female in the form of an android. Called Marionettes, they are built to serve men and are limited in their interactions with humans. That is until a poor boy named Otaru Mamiya encounters a Marionette named Lime. Lime is a Saber model with a special circuit that gives her emotions. When Otaru awakens two more Saber Marionettes, his life as an 'average' man quickly becomes as extraordinary as the lives of his eager, busty new friends.

The story revolves around Tsukune Aono, a boy who accidentally gets enrolled in a school inhabited by monsters and demons. He quickly befriends Moka Akashiya, a vampire who soon develops an obsession with his blood, and later meets other girls who soon take a romantic liking to him.

All of the girls at his college love Suou Tsukasa and come up to talk to him on a daily basis. Unfortunately for them, Tsukasa hates girls that are straightforward like that, but is too nice of a guy to tell them that.

In fact, he has a crush on Kizaki Megumu, his classmate and one of the shy and least talkative girls. The professor in one of the classes they have together is Dr. Hime, a young teacher whose childish looks and short height makes her a target for her students to jokingly tease and treat her more like their friend rather than a professor.

After taking home the drunk Dr. Hime, who was served lots of alcohol by her students, Tsukasa learns a giant secret about her love life.

Welcome to the cursed island of Shina Dark. This island is called home by the dark lord Exoda C. Claw AKA Satan. He's as powerful a being as you could ever hope to meet. Feared and hated the world over for the infinite amount of atrocities he's committed. He's.....actually a really nice guy who just wants to chill out around the castle and relax... After a month long nap he awakens to find that the rest of the world has made up another ridiculous rumor and blown it way out of proportion and that has caused his little island to be crowded with a thousand beautiful girls meant to be his mistresses/sacrifices. Worse yet is that since they have set foot on his island they are all believed to be cursed and are now shunned by their homelands. What’s a couch potato Satan to do with 1000 women who wont leave? Who can say?

From Operation Boredom:

During an eclipse, demon Lord Exoda. C. Crown was revived. He is supposed to bring chaos and destruction to the world. The world is panicking, and as a sacrifice to the demon lord, they decide to send 1,000 girls to the demonic island, Shina Dark. However, in Shina Dark, all the legends are lies. Exoda does not sleep with 10 girls a night, and keep the others prisoners. He does not lust for girls, he does not want to cause mass destruction - he simply wants to live in peace. So when 1,000 girls suddenly show up in his island and refuse to leave, what will happen to Exoda, who simply wants to be left alone?