?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?

From Turtle Paradise: After being shipwrecked on a remote southern island, Lina and Co. protect its townspeople from an attack by pirates…. But the island holds a deep, dark secret - and powerful magical forces are at work trying desperately to hide its past. The fate of the world once again rests in the hands of the over-bearing Lina Inverse… For better or worse! Join Lina, Gourry Gabriev, Zelgadiss Greywords, Amelia Wil Tesla Seyruun, and introducing Luke and Millena on a brand new adventure!

After meeting the enigmatic woman Hureika in a sideside village during her travels, the beautiful genius sorceress Lina Inverse’s fate takes a dramatic turn. Separated from her partner Gourry, she finds herself swept ashore onto an unfamiliar land. Faced with violent monsters, she is suddenly unable to wield her magic…. But her grand adventures only begin once she is saved by Lyos, a boy who claims himself to be the “Knight of the Aqua Lord”….

Alternate retelling of the Slayers TRY anime.

Koyuki has the power to see the future, but she can only see the unfortunate things that happen to people. Until the day she meets Umehachi, a high school senior... Fanservice, mayhem, and hilarity ensues.

A short story about the demon king and her loyal servant, Aslia.

Eratarou Kamegashira is a normal guy. All he wants is to live his high school years in peace and tranquility, hopefully making a girlfriend or two in the process. However, his brother Maratarou is a gigantic pervert. Due to Maratarou's shenanigans, Eratarou has been having trouble making any girlfriends due to being associated with him. However one day, the beautiful Takahara-san asks if she could visit Eratarou. Will Eratarou be able to keep his cool and win the girl, or will his brother cause things to "heat up"? Find out in the Kamegashira Brothers!

Ryota plays it cool around all of his classmates, especially when it comes to girls. But he’s always the one on the spot in a perverted situation. In some of these many random anecdotes about the lives of fifth graders you'll find: peeping at collarbones, eating chalk, accidental skirt flipping, missing bloomers (you know, those girls' gym shorts things), and many others. Who says grade school can't have a high-school-type love story?

Billed as Hayashiya Shizuru's "much-anticipated manga debut" it's a story of demon-possessed video tapes and Kurebayashi Mieko the "v hunter" who battles them. But in truth, she's just a pervert who *only* saves pretty girls!

Kurosaki-sensei is an isolated science teacher seeking to gain popularity with her students. Watch as she tries to win the hearts of her students!

Average, everyday Japanese gameaholic gets sucked into an alternate world where he has summoner powers and life keeps turning out to be like one big video game

Ai Shiratori is your average junior high school student with a crush on a boy, Hikaru Kamishiro. With a love so rampant and true, and an imagination as wild as any girl's Ai sometimes has rather... ecchi dreams. But none of those dreams could ever prepare her for the reality that came to her in the form of the Archangel Raphael. You see, Hikaru Kamishiro is not your average boy. Hell has plans for him and Heaven isn't about to let those plans come to fruit. While Hell sends their Hell's Apostles to get Hikaru to commit the seven deadly sins and drag him into hell, Heaven sends their secret weapon: Ai. What is Ai's mission? Nothing short of consummating her love with her beloved Hikaru... but wait by consummating you mean... sex?! Can Ai handle the Archangel's request and save her true love?