Leon was reincarnated in the world of an otome game that he was forced by his sister to conquer just before his death. He tried to live a peaceful life as a mob character, but he encountered a scene where a female student ignored the flow of the story and tried to become the main character. Leon ended up seizing Marie, a girl who had a similar atmosphere to his sister from his previous life, and succeeded in thwarting the scheme. It should have have been the right choice... but why was he feeling uneasy about it?

From MangaHelpers:
Nogawa Izumi is a good student, and a class representative, but she has an increasingly high libido. It's gotten to the point that she'll claim to feel bad during class, so she can run to the nurse's office and masturbate. When she learns that the Earth is being invaded by aliens that look like people dressed up as animals, it turns out her high sex drive may be able to help protect the Earth. The first time Izumi is attacked by the aliens, she is rescued by Usayama, a bunny alien whose race was their previous victim. Usayama gives her a swimsuit that will allow her to fight the aliens, but which also sends her constant arousal through the roof. The scientific organization that Usayama is affiliated with think that Izumi, with her high erotic level, may be the person they've been looking for to fight the aliens. Will Izumi be able to save the Earth?

A male to female ratio of 1:359?! Saotome-kun is admitted into a school full of gyarus.

???: Alright, let’s keep it up and do the heave-ho
???: Heave
???: Ho
???: Heave
???: We can heave-ho all we want but I think we’re all screwed because of that guy.
The Coin market that goes beyond the dimensions, A newcomer has appeared and turned the Dimensional Trading Center upside down!
Erun Steelguard, the enemy of all traders.
He was actually living his second life, after losing all of this wealth to dimensional trading and dying a tragic death.

“I am not the pushover I once was!”

Yusung is a genius doctor famous in the medical world.
He, who spent his whole life in an operation room, died in a traffic accident, and when he woke up, he was in another world.

But…a saintess? A holy empire? Healing magic?

“I put so much effort into learning medicine, but now all I need to do is touch someone and they’re healed?
Seriously, I think I’ve gone crazy.”

The protagonist Chan, who was looking for a part-time job after his previous company went bankrupt, coincidentally discovers a convenience store. Lured by the very high hourly wage, he decides to become a part-timer from that day. But the customers who come in seem a bit strange. Vampires, kobolds, and even succubi??

From Viz:
In the 21st century, just when the human race needs new heroes, the Lucifer Hawks enter Earth's dimension. The members of the A.M.P., six young women with incredible powers, are set to defend the human race against these monstrous entities from another world.

After his first drama flopped, Lee Hyunseok gave up on being a PD. But when he finds himself being granted one last wish in his dying moments, he wants only one thing: to produce the ultimate makjang drama. Now, he's been given a second shot at life (and the assistance of a ghostly PD), but he's on a time crunch to achieve ratings and recognition. With no budget, rookie actors, and an amateur writer, Hyunseok's got his work cut out for him. But what's a good drama without a few twists and turns?

Chun Hajin, the strongest assassin of the Orthodox Murim’s Righteous Heavenly Alliance. Hajin loses his life as he tries to escape to find freedom.

And then…

‘The divine cult is immortal, may all demons submit. Congratulations on your recovery, third young master!’

He was reincarnated into the body of Murim’s public enemy, the third young master of the Demonic Cult?!

The conquest of the Demonic Murim by Chun Hajin, the strongest secret weapon of the Orthodox Murim, begins now.

Ghislain Perdium, the Mercenary King and one of the continent's top seven, started a great war in an attempt to avenge his fallen family.

His plans of revenge were going smoothly until he was slain by Idun, who he had never expected to make an appearance. Ghislain thought he died, but he woke up as a younger version of himself from before the fall of his household.

With this second chance, he decided to fix all the wrong pieces of the puzzle and avoid making the same mistakes he did in his past life!

The war ended with the defeat of the villains. Now the world is ruled by corrupt heroes. And one of those heroes killed Yihwa's unni. She doesn't know which one, but that doesn't matter. If she kills them one by one, they will be among them. Yihwa becomes the Hero Killer, a villain who hunts heroes every night. This one villain's vicious action fight. "I'll kill everyone, and take everything away!"

Taken from Baka-updates: Yuri Shibuya was living a pretty normal life. That changed the day he was dunked into a toilet after an attempt to save a classmate from a gang of bullies. Instead of just getting a good soaking, he's pulled in. The next thing he knows, he's in a world that vaguely resembles medieval Europe. If that's not odd enough, he's told that he is to be the next Maoh, just because he has black hair and black eyes. The Maoh is the King of the Mazoku, who are coexisting not-so-peacefully with the humans in this world. Much to his subject's dismay, he's totally different from the rulers they're accustomed to. He's kind, considerate, a believer in justice, and not willing to use violence to solve conflicts. Not exactly someone they want running a country on the very brink of war. Now, Yuri has to deal with trying to become a good Maoh, while at the same time attempting to adapt to this land's customs and culture, all in a world where the tension between the humans and Mazoku is reaching its peak.

Park Sooho returned to Earth after disappearing to another world for a thousand years. During that time, Earth had changed into a world of the survival of the fittest thanks to the appearance of monsters. Druid, the king of the animals, who had managed to survive for a thousand years is now off to conquer the world.

How many kicks does it take to smash the heart of a giant? Though she’s not a pure Child of Golden Light, Loxy must learn to channel the sun’s warmth and topple the towering titans that stand in the way of saving her sister. With bloodthirsty giants in her path, and the ruthless God of the Gods, Odin, in hot pursuit, Loxy pushes her body to its very limits in the hopes that she can become half as strong as the sister that now desperately needs her help.

It was an era of terror, a time in history where 10 suns shone as the world below burned under its mantle. As a result, Yae, a legendary warrior, was summoned and commanded by Chunjae, the father of these 10 suns, to shoots down all but one sun. But of course, the suns’ mother, Hwaehwa, did not take this news well and, in vengeance, swore to revive her dead sons. After a long time, Hwaehwa returns and challenges Chunjae to a game of Baduk. She brings Hanbal with her, who was once Chunjae’s follower and releases a thousand demons down to earth, proclaiming that they are a symbol of her Baduk stones. Now, in order for Chunjae to gather his stones, he searches for Dong Bangsak and provides one of Yae’s followers, Hangah Dong Gun (東君) to watch over him as he embarks on his journey to seal these demons...!

Maeda is a new student in the Teiken High School. He stutters when he's nervous and he's rather clumsy. He gets noted immediately because he hits a teacher during the entrance ceremony. Some clubs search to enlist him as they see in him a force they can use to get even with other clubs. But Maeda is a loner and has only one dream: becoming boxing champion. His first objective is to beat the leader of the boxing club. "Rokudenashi" translates as "good for nothing".
The manga focuses more on gang warfare than boxing.

Humanity’s home is no longer Earth. Intersellar travel is now a common occurence, and technology has replaced blood and flesh.

Luka, who grew up in the slums, has turned fifteen and taken the selection exams. His aptitude is of the Imperial Guard.

It was in the year 2800 of the Midgard calendar. Back then, there was a Overlord who once reigned supreme and had reached the very brink of subduing the world. Her name was Lufasu Mafaalu, a great woman dreaded as the Black-Winged Overlord. She was too strong, too fast, and too beautiful. However, she was defeated by Heroes who opposed her ferocity, and her ambition was brought to an end.

Or so went the story of our protagonist’s in-game character, whose body he now possesses for some reason in a world 200 years after Lufasu’s downfall. Follow our protagonist as he becomes unnecessarily feared by his surroundings and unnecessarily worshiped by his former subordinates as he―or now she―cheerfully travels around this fantasy world.

The Post-Apocalpyse and starting a Newlywed Life with an Angel.

I killed the player.

He was a real son of a bitch…

He loved me too much and was a sociopath.

Now that I'm back in time, I'll kill him before being manipulated again and save the harem's girls who will help me win the video game's scenario!