From MangaHelpers:
Before they enter high school, the boys Meguru and Shou are whining about the fact that neither of them has a girlfriend. A strange, large-breasted woman shows up, claiming that she will fix their problem, and kisses Meguru. This odd occurrence is pushed out of the boys' minds when they meet up with Souko, a friend from elementary school, who is going to be in their high school. She's grown up into a pretty young girl, and it seems like the boys might have a shot with her!
That evening, Meguru realizes that the strange kiss may have had more meaning than he thought: he's turned into a girl! He convinces Shou and his mother of his identity, but no one has any idea how to turn him back. Now he's going to have to learn how to be a girl and let go of his hope of dating his cute childhood friend Souko. What will happen to his hopes for a popular high-school life?

Randou Masashi, a self-centered, brash karate star, was the victim of a horrific bus accident that left him comatose, his face terribly disfigured by extensive burns.

Genius plastic surgeon Dr. Manabe saved Randou's life and went to work on his face, gradually reconstructing it based on a photograph found in the wreckage of the bus. But in a cruel twist of fate, the photo that the doctor used as his reference was not a picture of Randou, but of Rina Kurimi, the girl whom Randou has a crush on!

From Pink Everlasting Dream Scanlations:

Sakura Aki is a penniless high schooler who likes to cook and does other "unmanly" things. His grandfather and father are disciplinary on gender roles and beat up Aki everytime he does a thing that women would usually do, like cleaning. When his father leaves him absolutely broke, and with his grandfather realizing Aki's "unmanly" flaws, he sends him to live at one of the dorms at an all girls' school that he runs, a school where distinguished young ladies of the country attend, the Hanayashiki - Flower Estate-, to teach him a lesson.

He meets Kitahiro Renge, a girl with un-ladylike manners and a meat loving obsession. An encounter that's going to save Aki Sakura or just another problem in sight?!

Konoe Subaru, a classmate of Sakamachi Kinjirou, has been serving as the butler of Suzutsuki Kanade in school. Due to an accident, Sakamachi discovers Konoe's secret...that he is actually a she!? Apparently she will be removed from her position if anyone at school finds out. What will unfold from this chain of events?

Hinata Saotome is suddenly asked out by En Shinohara, a gorgeous boy in her grade. What she doesn’t know, though, is that his hobby is cross-dressing! En has always hated men, and whenever he sees his own reflection, he punches out whatever is doing the reflecting (windows, mirrors…). To combat this hatred, he dresses up as a girl. Hinata decides to go out with him anyway, despite his weird hobby.

Also included are the following unrelated short stories:

• Sweets Honey (V.08)
Serizawa gets sick whenever she smells something sweet, but she likes a boy named Miura who has an extremely sweet tooth.

• Boy's Lily (V.16)
A spin-off of Usotsuki Lily where En is a normal guy who recently started dating Hinata whose hobby is dressing like a guy.

• Amber (V.17)
Mio Hasekura is a helpful high school girl who is very fond of her late father who died when she was younger, and hopes to find a guy like him someday. On her way to school one day, she comes across a man collapsed on the side of the road and Mio helps him out.

From Viz:

It seems like 15-year-old Kazuya Hasukawa's life can't get much worse. Not only did his older brother marry Kazuya's first love, he brought his bride home to live with the family! Leaving his own home, Kazuya enters an exclusive all-male boarding school, Ryokuto Academy. Unfortunately, a prestigious education is little compensation for getting stuck with the cross-dressing roommate from Hell...

Note: There are more volumes in the original Japanese publication compared to the Viz release because Viz has excluded unrelated one-shots that do not involve the Greenwood characters.

Hatsushiba Akira, an awkward high school senior boy, has a strong crush on classmate Sakuraba Yurika. But when he gets close to her, he always says or does something stupid.
At the suggestion of his best friend, Kikuchi, Akira enters the GachaGacha machine to play a game, but the machine fritzes out and malfunctions. That night, he sneezes while going to bed, and when he wakes up, he looks like the female avatar he saw in the GachaX2. He soon learns that sneezing will change him back and forth from his normal self to a female form. As a girl, Akira-chan is able to get close to Sakuraba and to become her friend.

Lately, Kouhei can't get his friend Kurara out of his mind. Even though he has known her since elementary school, all of a sudden, ever since she came back from summer vacation, he has been crushing on her... hard.

But something is different about Kurara--she's acting very oddly. Sometimes she seems wholesome, pure, and innocent, and at other times she is extremely forward and unabashed. Kouhei soon learns that Kurara has multiple personalities--and decides to help her keep her secret from their classmates. But Kouhei finds himself struggling between helping Kurara as a friend and trying to win her heart... which is a challenge, since she has many!

A boy is forced to dress as a girl to be a Mannequin for his sister's fashion designs, its a trap one shot from oto nyan

Ralph, the Tyrannosaurus, is the king of the dinosaurs. However, because of a meteorite's impact, Ralph is sent 60 million years into the future only to possess the body of a honours student, Mikobayashi Kana.

Sakurai Tomoki is a normal student whose motto is "normal is the best". If there is one thing abnormal, it is that he often dreams of a girl whose face he cannot even remember, and when he wakes up from that dream, he would always be crying. He tried leaving it as just a dream... but one day, from the sky, an angel descended.

From Divine Sanctuary:

Ogata Aoi is in her second year of middle school and is the president of the student council. The middle school she attends is one of the best in the country and is called "AAA." Aoi goes there to meet her first love, but after a surprising meeting, she's finding out that her first love is a gang leader in the neighbor school, called "CCC" (lowest level). Maybe it's only a coincidence, and that gang leader and her first love just happen to have the same name. After all, they look completely different from each other. But now, Aoi wants to find more about this person...

From JShoujo Scans:

Little Rin Fujiwara hated her own face a lot. It was not until her 6th birthday that a make up box she got as a present changes her perspective completely. In front of the mirror, Rin would play with the make up, which becomes like a magic that makes her stronger. Rin believes make up can change both appearance and heart, because it gives the confidence a girl needs.
Years later, Rin attends her first high school year. She decides to help other girls there to become pretty as well, using her make up box. Rin, hidden under the identity of Ageha, a legendary make up stylist, with a help from her classmate Kisaragi, who has to hide his real identity by crossdressing as a woman, is willing to do magic in front of the mirror and change girls “just like when a caterpillar transforms into a butterfly”. How to meet Ageha and have her make you more beautiful? Easy, just write your name and class on the butterfly card and put it on the bullentin board on the 3rd floor. Ageha will come for sure, so what are you waiting for?

Amamiya just died. Death by bottle tripping... But he is given one more chance, to live... To live in the body of a girl gone comatose, that is. With his new identity, read on how his mind set is slowly changed from a guy to a girl. One thing's for sure, there is more than one body switching in this manga!

The main character is a trap, whose sole purpose is to convert others into trap by whatever means possible. He seeks boys with feminine features or behaviors and through very comedy based tactics convinces them to embrace the trap life style, and often ends up helping them out in some way.

The angel Alexiel loved God, but she rebelled against Heaven when she saw how disgracefully the other angels were behaving. She was finally captured, and as punishment sent to Earth to live an endless series of tragic lives. She now inhabits the body of Setsuna Mudo, a troubled teen in love with his sister Sara. Setsuna's misery mirrors the chaos among the angels, and their combined passions threaten to destroy both Heaven and Earth.

From Iskultrip Scans and Manga Abyss:

Maria Rose, a boy always mistaken as a girl, is burdened with debt after a strange event, and his sword, "Fake Consuming Inferno" is confiscated. At that time, Katari, a member of his clan, got a hold of some profitable information, but to obtain it, they have to go to an "Underground Raid", but things aren't as easy as it seems...

This is the story of love, friendship, and adventure of the beautiful "Cracker", Maria Rose.

A collection of oneshots.

• Gokudou no Oujisama (Gokupuri - The Hoodlum Prince)

• Oujisama no Kaikata (Raising a Prince) -
Rich Prince Zeroji, who has come to be continually bullied, is a peach?
However Zeroji has lost his memory!
Heheh! This is the chance for “revenge”!
Look forward to Saijou Ayano's spirited romantic comedy!

• Bishounen Shichihenge
After being dumped by her boyfriend, Satuki is ready to hang herself. As she ties the rope and reflects on her life, these annoying brats start making a racket behind her! Can't a girl die in peace!? She runs them off only to find an innocent fat boy in their dust. He was being bullied, and she saved him. This surprisingly tall chubby-chunker wants to repay her; so, he'll become handsome and attractive for her, just like the model JK! Once he's handsome, he'll pretend to be her boyfriend to help get back at her ex! Now that he's attractive, she's having strange feelings... is she falling for his look or for the chubster inside?

• Pet Katte Mimasen ka? (Won't you try to raise my pet?)

• Motto Kikasete... (Let me ask more...)

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High-school student, Yukiji, whenever he's with a girl, he would get very anxious around them. As a result, during the school's festival, he encounters a long haired beauty dressed as a maid and falls in love with her at first sight. Unexpectedly, he finds out that the beauty was actually his fellow classmate... Haruki. Every time he's around the cross dresser Haruki, he feels an uncontrollable urge.

How can that be?

Includes two chapters of "Lost Lamb, Please Take Care of Yourself".