Even the oracle, the one who is meant to locate the Dalai Lama's reincarnation, could not foresee that the troublemaker Dang would be the one taking on the crucial mission. However, Dang's power posses a hidden; his true might is shown when his chi explodes due to sexual impulse and turns him into a monster! Not knowing this, Dang enters Mouhyuk High; following the oracle's orders. But his class is a special class meant for "Trash", filled with a bunch of weirdoes, and his biggest enemy, the "Coke Bottle" shaped woman! Can he complete his mission?

From Evil Flowers:

During their senior trip on the cruise ship Victoria, a group of friends is suddenly pulled back in time and separated. The main character, Hayumi Natsuki, arrives in the year 1636. In Japanese history, Christian rebels, led by a young man known as Amakusa Shirou, revolted in 1637, which resulted in thousands of casualties.

However, when Natsuki arrives in the past, she and her friend Eri discover that Shirou Tokisada is already dead. Meanwhile, Natsuki, according to the villagers and Shirou’s parents, looks exactly like their late son (disregarding the fact that Natsuki is female).

Natsuki, the kendo champion of her school and heir to her family’s Hakuhouryuu kendo style, simply cannot stand by and watch innocent people be persecuted simply for being Christian. Soon she even becomes known as an angel, sent from God, whose arrival was prophesied 25 years earlier. But what will she do when old friends become new enemies?

A boy who loves genderswap got genderswapped, so he acts out his ideal genderswap girl.

From MangaHelpers:
In this world, there exists individuals known as "Majin": supernatural beings able to wield unique powers. They live among the normal human beings, but the divide created between the Majin and the normal human race is severe. There exists a school known as Dangerous, where the population ratio of Majin students exceeds that of any other high school. In this school, two groups known as the "Banchou Group" and the "Seitokai" face each other in war, but they have created a balance of power, resulting in a temporary peace. Now, with the inclusion of new students, this balance of power is about to collapse. One of the "normal" students, Ryouseiin Otome is forced to choose sides before the beginning of Armageddon.

The guy who served as an assistant for an adventurer party, ■■■■■, was betrayed by his party members on the dragon-infested Mt. Kuguse. Mortally wounded, he wakes up later in the nest of the Red Dragon, Kafal, who lost its eggs in the disaster. He has become a girl called Lushela, having been bestowed the name of the dragon's dead daughter, after losing both his memories and his name. It seems like Kafal's started to raise him as its own daughter...? A unique parent-child tale of how one dragon and one human's strange fates bring them together.

Shirokawa Sasane (30) is a former trading company employee and a huge fan of Romance of the Three Kingdoms. One day, after losing consciousness in Chinatown, he wakes up to find himself in the form of a little girl. However, the new body he finds himself in isn't just any little girl, but the granddaughter of the infamous tyrannical Dong Zhuo, Dong Bai. In order to avoid the fate of being executed alongside Dong Zhuo, Dong Bai will have to use both experience as a Japanese businessman as well as knowledge of the era!

Kuji Akira and Ninomiya Makoto have been neighbours and friends from childhood. Akira is handsome and Makoto is pretty but Akira's a girl and Makoto's a boy... Their feelings for each other are growing more complex just as they are finding themselves the focus of romantic interest of their friends and acquaintances.

Two brothers, Noboru and Toru grew away from the fact that their family could use the Water ki to keep demons away. However, in order to keep Toru safe after a demon goes after his life, they will need to awaken the fox deity Kuugen.

Guy turns into girl whenever he gets excited.

Izumo Kunisaki, a descendant of Izumo no Okuni, is often mistaken for a girl. It is the bane of his existence. His father and best-friend often laugh about it. To top it off, he plays the girl roles in his family's Kabuki troupe. In this short, he discovers that that curse is also his greatest source of strength and will prove just how much of a man he is.

A high school student Ichi who visited a ninja residence on a school excursion was caught in a strange structure during the tour and time slipped to the ninja world. Along with his friends, Ichi who got the “Ninpocho”, a key to return to the present age, returns safely to the present age. However, suddenly an awakening appears in front of Ichi who lives a peaceful life ...!?

Male high school student Shikayama always keeps his distance from his classmates. He has neither friends nor a lover, but always makes sure to get home before sunset. Because...

Imamura Hinata. A high school student, who has a complex. Everybody thinks he is a girl.
He wants to get more masculine, no matter what. Until one day he finds a strange advertisement...

On a school trip to shinobi-themed Ninjatown, a young man named Ichi Kuno accidentally springs a mystical ninja trap which sends him back to the Age of the Ninja. Having no other path, he must pose as a girl and infiltrate Kurenai Academy, a school of kunoichi students, to retrieve a mystical scroll that can return him to the future. But when everyone around him is already far better at stealth and infiltration than he could ever imagine being, it's not going to be easy. He'll need to employ his own special bag of tricks, and have a lot of luck, if he's going to last more than 5 minutes surrounded by hot kunoichi girls, every one of whom would happily kill him in a moment if he's discovered.

Two girls who want to become idols are entering into their long dreamed school—Kiraboshi-juku—Kiraboshi Nadeshiko and her close friend Mangetsu Sakurako. These two are so close that despite both being girls, they're often compared to a married couple by people around them.

And so begins their life in the dormitory as roommates. However, on their first night, an unusual, illicit impulse strikes Nadeshiko...

[From Viz]:
Being a teenage martial artist isn't easy, especially for Ranma Saotome, who went through a major transformation on a training mission with his father. After an accidental dunk into a legendary cursed spring in China, Ranma now changes into a girl every time he's splashed with cold water. That would be enough to complicate anyone's life, even without the arranged fiancée who doesn't like him (or says she doesn't) and the constant stream of rivals and suitors for both his male and female forms. What's a half-guy, half-girl to do?

Kazuyoshi Ishii has had a bad day. The former director of K1, one of the world's greatest karate tournaments, was arrested for two years for tax evasion. Just as he is released and he can return to karate, he is struck by a truck
However, just before his death, a talking cat appears before him. The cat explains that while Ishii is dead, it can give him a new life - so long as he can complete a task for it. With no other choice, Ishii agrees. Succumbing to his injuries, Ishii falls to the ground, dead
At that moment, high school girl Kei Ichinose wakes up from a three-day coma

Etou Shougo is a university student sharing an apartment with his male childhood friend Yoshizawa Natsuki. When Natsuki leaves to take part in a clinical trial Shougo didn't know he would be coming back as a girl! It looks like Natsuki won't turn back into a guy for a whole year. Rather than worrying about it pointlessly, why not have some fun with it instead?

Asuka, transfers to a dormitory, but after meeting his roommate, Asuka realises that someone must have confused his gender and assigned him to the women's dormitory. Asuka's roommate, Yayoi, says that there's no problem with Asuka living in the women's dormitory and quickly brings out complementary articles of clothing so that Asuka can crossdress.

Outside in a park, Asuka bemoans his current state of affairs until some weirdly-dressed woman appears, and after listening to Asuka's plight about being assigned to the wrong dormitory, the mysterious women decides to fix things by transforming Asuka into a girl before running off. Yayoi appears and finds the newly changed Asuka, he explains to Yayoi what happened, and Yayoi believes everything and points out that now there is no problem with Asuka living in the women's dormitory.

Later, in the dormitory, Asuka discovering the good things and bad things of being a girl ; enters the bathroom while Yayoi is taking a shower and finds out that Yayoi is really a guy. Though, to be clear, Yayoi explains that he isn't crossdressing but rather wearing his uniform. Asuka then becomes worried about being in the same room as Yayoi, but Yayoi is interested in nothing but hot bishounen.

So now Asuka is living in the women's dormitory while trying to find the mysterious woman again so that Asuka can change back to normal with the help of Yayoi who, of course, has an ulterior motive for helping Asuka.

Ha-Ru is the daughter of a family that rules a remote island--she is also the heiress to this secluded land, something that Ha-Ru's half sister, Mi-Ru, resents. When Mi-Ru becomes upset and runs away, Ha-Ru follows her--and magically they are ushered into a foreign desert! And in this land, it's survival of the fittest!