Lelouch, Suzaku and other young warriors battle in the late Tokugawa Shogunate era, where the power of Geass forced Japan to falsely open up their ports!!

The curtain rises on an alternate world tale of Code Geass!!

(Taken from Bandai Entertainment)

Hinazato Tsugumi, a normal girl, accidentally got picked as Miss Madonna for the Shiratori Girls School, a very select girls high school for the rich. So now Tsugumi, a girl from a middle class background, is attending Shiratori and trying to adjust to being the centre of attention amidst all of these high-class people. Of course, she's not ashamed of her background, and she's very high-spirited and cheerful. Takaomi, a slacker from the private boys' school next-door, is exactly the opposite - apathetic, and always napping outside. How will they deal with each other?

After being bullied at his old school, Makoto wants to be the main character of his own story. When he finds a bill with his face on it on a school trip to Kyoto, he takes it as a sign, which leads him to fall into a river. Once he comes to, he realizes that he has been transported back to the period of time in Japan known as the Bakumatsu!

From Iskultrip Scans:

A long time ago…
there was a disease that would cause nightmares and kill people. Doctors and wizards threw in the towel, unable to find a cure. All of a sudden, mysterious magicians appeared. These magicians ate the nightmares of those who suffered from them. It was said that those who had their dreams eaten were able to sleep peacefully.

This is the story of “Baku”.

One day when average middle schooler Koji Miyahara came home from school, he found a naked girl sleeping in his bed. To his surprise, she was a ghost, and her name was Alice Fujinomiya! Alice can only be seen by other people when Koji's nearby, so she decides to become his girlfriend.

Taichi Yamada is what you would call a fan but he is not just any fan, he is a fan of Kokoro Shiina, a gravure model. Maybe it was fate that brought them together that day but Taichi met Kokoro when she literally fell from the sky. Waking up in the hospital, he begins to see Kokoro's spirit and after roaming the hospital premises a "shinigami" arrives to take Kokoro to the underworld. Is this the end for Kokoro? What will Taichi do to save his beloved idol?!

"I," an aspiring novelist who can’t land a hit, a normal college student. Kai Shouko, a female college student writer who produced a string of hits. During the welcoming party of our university, a naked idiot suddenly barges into my life.

Oumi Shigemori, also known as Hanjo, is from a long line of merchants. He knows the tricks of the trade when it comes to business and making profits. But Hanjo understands that profits have to be long term and taking short cuts in business decisions eventually leads to a collapse. Making sure the buyer, the seller, and the community all benefit from the transaction is Hanjo’s philosophy. He travels around the country, helping both small and big businesses turn their finances from a molehill to a mountain.

Shizuku Utsugi, an energetic girl who grew up on an island, leaves it and started her life on the mainland in order to go to high school. Her mother set up only one requirement: “for the next 3 years, just enjoy your school life”. Joining the lacrosse team carves out the path she will be taking.

This is a no-holds-barred story about an ex-biker gang leader turned cop, Kenji Date. Operating under the nickname Hyena, Date rubs pretty much everybody within the police force the wrong way as he goes about his business ridding the city of all its scum.

Bad Police also contains two separate short stories at the end of the volume:

Bomber

The Chinese leader, Deng Xiaoping, had promised to rid Hong Kong of its criminal organizations. One of the places they migrated to was Japan. Kamon Shou is a delinquent who just got released from Youth Detention after spending two years there and is about to feel first-hand the effect the Hong Kong mob has on Japan.

Artemis

Ginko is a detective working for the famed Holmes Detective Agency, an agency that takes on the most dangerous of jobs: ones that even the police wouldn't even think about doing. She gets hired by Ms. Nancy to retrieve her seven year-old son, Tom. Tom was taken away by her father-in-law's mafia organization in hopes of cultivating Tom to become the next leader.

Kazuki's had a 16 year grace-period of peace and relative normalcy; smuggled to Japan and raised by a kindly old woman he's grown up to be a bright and friendly boy. His childhood friendship to the girl next door is just beginning to blossom into romance and the death of his ward leaves him with enough character-building angst to set him up for just about any cliche shoujo adventure Yukari Ito has in mind. Unfortunately, Yukari Ito is TOTALLY insane and has decided to make him a vampiric kitten engaged from birth to a Nightmare. (from doki-doki)

From Twisted Curiosity:

Meguru is an ordinary schoolgirl on a school trip. They stop to take a break and she is determined to confess her feelings to the boy she likes, Yashiro.

When they get back on the bus, however, a strange man grabs her and says that he's bus-jacking them. He shoots Meguru for putting up a fight and she thinks, fading into oblivion, ?I wish I could go back in time?. The next thing she knows, she has woken up in her bed at home and quickly finds out that it's the day before! What in the world?

From Tokyopop:
In the future, random Jr. High School classes are chosen to compete in a game called Battle Royale. The rules: only one student can survive after 3 days on an island or else they all perish. Weapons are handed out and each student is sent out into the field alone and unprepared for the horror that awaits them. The classmates turn upon themselves in a battle for survival, treaties are made and broken, and former friends become foes as the relentless countdown continues. Amid the betrayals and rising body count, two classmates confess their love for each other and swear to survive this deadly game together.

Note: An English-language release of the collected volumes, published in the United States, Canada, and United Kingdom by Tokyopop, was extensively rewritten by Keith Giffen, whose script does not completely follow the original manga. This adaptation makes several changes to the plot. Most notably claiming "the program" is a reality TV show and changing the time that the story is set in by almost 10 years, both of which are contradicted in later volumes.

Like the earlier Battle Royales, a class of middle school students are picked to compete in fights to the death on an island until there is only one left.
The manga follows the point of view of Girl #10 Makoto Hashimoto, an unlucky girl who fears that her class will be chosen to participate in "the program," a mysterious event that forces students to kill each other. Makoto attends Shikanotoride Junior High School. After the encouragement of her best friend Itou Yamamoto and her mother she decides to face the chances. Her fears are supposedly put to rest when word spreads that all 50 Programs had already been executed in the year making them 100% unlikely to participate....

"Basara - The spirit of freedom which denies old authority, transcending traditions and customs."

Born under a prophecy that will liberate and unite Japan, Sarasa has had to take her brother Tatara's place as the "Boy of Destiny." Fighting for the oppressed, Sarasa journeys across Japan to gain allies and defeat her enemies--all while keeping her identity a secret!

Basara won the Shogakukan Manga Award for shoujo in 1992.

From Viz:
Nature made Ash Lynx beautiful; nurture made him a cold ruthless killer. A runaway brought up as the adopted heir and sex toy of "Papa" Dino Golzine, Ash, now at the rebellious age of seventeen, forsakes the kingdom held out by the devil who raised him. But the hideous secret that drove Ash's older brother mad in Vietnam has suddenly fallen into Papa's insatiably ambitious hands--and it's exactly the wrong time for Eiji Okamura, a pure-hearted young photographer from Japan, to make Ash Lynx's acquaintance...

Yukikaze is just a young girl but her and her friends have the incredible responsibility of being the naval force of her nation. As part of Seiran Team 3 of the Wadatsumi naval base, Yukikaze and her female friends, Isokaze, Nowaki and Takao, all attend the naval academy. But in this world, they do not work on ships, instead, they themselves are the weapons, able to travel across oceans at high speeds and engage in warfare using their equipped artillery. When an enemy nation attacks the base to take control of an important strategic point, only Yukikaze is left standing and all hope seems lost when a beautiful woman named Taiwa appears with the secret weapon to defend Yukikaze and the naval base.

From Vampire Knight:
Ai was your normal, everyday grade teenage girl until one day, she was involved in a fatal car accident. In the hands of the Specialized Secret Police Organization, she was able to be revived. With her newly gained powers acquired through the operation, she becomes a defender of justice. With the mysterious (and a little perverted) bishounen Sagiriya Shinogu as her partner, she fights the forces of evil!