In a world where the demon lord had been defeated and peace had arrived, Rex the magical doctor ran a clinic. But the patients brought in were all beyond saving compared to the world itself, people who'd XXX slimes or stuck their peens into man-eaters!? An otherworld perverted medical comedy begins!!

Uichiro, a junior high school boy, harbors a secret he cannot share with his childhood friend, Tama-chan. He has been cross-dressing for her because she has a phobia of men. This is a thrilling yet agonizing comedy about a boy who cross-dresses for the girl he loves!

Seeing it brings misfortune; defiling it brings a curse? Introducing a new era of strangeness, abandoning seriousness!

On a stormy day, a landslide destroys a fence, and siblings who ventured into a long-prohibited area encounter a terrifyingly bizarre creature...
"I'm a curse god, you know!? Don't you think anything of this grotesque form?!?"
The unflappable siblings, rather than being scared, casually call the creature "Dara-San" and grow fond of it!?

Seemingly scary but not at all! A new era of occult comedy that leaves seriousness behind.

"I've been cheating on you. Oh, and it's not just one guy. It's three. Sorry about that."

Back in middle school, Akiyoshi Sunao's first-ever girlfriend shattered his heart, and he swore off love. However, all that changes when he develops a crush on a girl in his university's film club. Just as he's finally beginning to move on from the past, he bumps into his ex-girlfriend. Little does he know that this is only the beginning...

To his horror, he wakes up in her body the next morning!

As the master of the School of Unholy Arts and as the undefeated Unmasked Demon, MookHyang unfortunately falls to a strange fantasy world by the magic of his enemies (School of Blood Arts). In the new world of elf, sorcerer, knight, and dragon, MookHyang’s adventure of finding a way back to his old world (Murim) unfolds.

Kang Ji-hoon, an ordinary high school student who died in a painful accident, finds out in the underworld that he is actually a ‘Water Spirit King mistakenly born as a human’. “Making water spirits? How do you do that?” The adventures of Elqueeness, the Water Spirit King who was mistakenly born as a human!

From MangaHelpers:

Utilizing a system called "Sense," each player aims to create their unique character in the VRMMORPG "Only Sense Online." Joining this realm is Yun, an absolute beginner in the world of gaming, equipped with some of the worst customized "Sense" ever. While his two sisters, both veterans in this world, criticize his choices of equipment, he continues to delve into the skill sets he has acquired. Along his way, he meets the art of "production" and people that have mastered this art. Watch as a total novice creates a revolution in the gaming world and create the "ultimate" support class. [DrCoke]

Albright, who was famous as “the strongest Black Knight”, was reincarnated as a girl, Maria, whose ribbon suited her well for same reason. Maria, 16 years old, is currently a maid in the Marquess of Urband family in attendance to the Daughter of the Marquees, Relena. After Relena became engaged to the 4th Prince, the area around Maria had gotten busier…

After two years of being dormant inside Tsutomu Senkawa, an accidental encounter with their old nemesis violently wakes Birdy up. With Birdy kicking evil's ass once again, the dark secrets of the experiments conducted by the "Agni" corporation are slowly revealed. They seem to be dabbling with human body enhancement, creating what they call "beast men," to combat the alien invasions related to Birdy.

A dull old man and his handsome best friend were summoned to another world by a naked goddess! However, because of the goddess's mischief, he has turned into a peerless beautiful girl?! To get back his body, he has to go on a journey with his best friend to defeat the demon king!! "An old man that became a beautiful girl" and "A handsome old man"! Let the madness filled another world journey rom-com begin!!

Tasuku Nakamura, who was thrown into the sea in a marine accident and tried to help his best friend, ended his short life of 25 years. Formerly a mediocre office worker, when he opened his eyes, he was in the form of a six-year-old baron's daughter, Sophie Linier. At first she was confused by the changes, but she was reincarnated as a beautiful girl and decided to live as a lady in a different world.

The middle school girl Mada Ooma was the Demon Lord in her previous life. She (he) has but one lingering regret. And that was the fact she wasn’t able to confess her feelings to Riri, her attendant, whom she loved in her previous life. A love that would never come true... or so she thought, when Riri somehow appeared in front of her eyes in her new life...!? A bright and pure romantic comedy crossing past and present lives about a former Demon Lord who’s being taken for a ride by the one she loves!

My name's Karina—or at least, it is now! I used to be a nondescript, run-of-the-mill Japanese salaryman until I was whisked away to a divine realm where the Goddess of Time and Space told me I'd be living a new life in a new world—and as a girl, since apparently she prefers it that way. First she wants me to beat some final boss she has a grudge against, then she takes control of my body to show me how to use my new spatial magic powers in a tutorial fight... Wait, isn't that the final boss I'm supposed to beat?! Less than in a minute into the tutorial and he's dead!? And now she says the world's my oyster. Seriously!?

Official English Light Novel: https://j-novel.club/series/knock-yourself-out-the-goddess-beat-the-final-boss-in-the-tutorial-so-now-i-m-free-to-do-whatever

"Haruka Yamagishi" is a guy who has no friends or family and just goes back and forth between work and home. One day, when he wakes up, he finds himself in a different world. And for some reason, he's turned into a beautiful dark elf! Now, Haruka has inexhaustible magic power, a sturdy body, and a new life where she can do anything... However, through the friends she met and her activities as an adventurer, changes slowly began to take place. The guy who gave up on life in this world begins to feel what it's like to live. Although there are some traps and other events, it's a touching adventure story!

[Source: Manga updates]

When the boy's soul enters the body of a girl, but what about he's able to destroy the demons in order to protect the world? A work of Jiu Ye has officially launched.

A hitman and a marriage swindler set out on the world’s most grueling battle for marriage! Gero is a young man from a clan of hitmen, which has been in existence for hundreds of years. As someone who’s never gone to school and lived his life dealing in the dark side of the business, he considers himself to have “no prospects with women” and marriage as “something not for him.” However, one day, in fear that their lineage would dissolve, his clan warns Gero that if he doesn’t marry and produce an heir, they would have no choice but to…force his little sister into doing “that.” Driven to his wits’ end, Gero asks the target of his work, a marriage swindler, to…

Uesugi-kun is a boy who's as petite and cute as a girl. He has a crush on a girl he's known since childhood, but overheard her saying, "Wouldn't Uesugi be totally adorable if he was a girl?!" Uesugi-kun's not as tall as his other childhood friend, Eito, nor is he as good at studies, and now he's suffering from a broken heart. A depressed Uesugi-kun stops by a shrine while running an errand and makes a wish... A love-triangle romantic comedy featuring an overly cute, and now female, protagonist begins!

In order to be bought by a rich family, Narumi Inoue, hiding the truth that he is a man, goes to a girls' school. As a trainee, Narumi was sent to serve a girl from a rich family who hates maids (only weekends). Keeping the 'heart of treating/serving people,' Japanese maid, Maid in Japan, Narumi's battle will start? If it is found out that Narumi is a man, he will be castrated.

Rin's village getting attacked by bandits doesn't keep her down in the dumps for long! Picking up a sword housing an extraordinary pervert… I mean hero, Siegfried, she sets off on a journey of many bouts with various degenerat… ahem, heroes!

About a guy who reluctantly transforms into a magical girl to fight monsters.