Iver is a dragon maou who stopped trying after historical heroes defeated her every time she resurrected. But the present day hero, Mirio, who found the holy sword by pure chance falls in love with her. And thus forms the couple of the maou with no self-esteem and the dopey hero. This is a story of how they come to know each other, fight, and find happiness.

Witches suddenly declare war against humans, causing two-thirds of the world to fall apart.
They summon monsters called "Supporters" and devastate human residences but why?
Survivors gather people with the power to combat the witches and called them Witch Hunters! Tasha Godspell is one of the strongest nicknamed "The Marksman" along with his "Jack-O-Lantern" looking Supporter. He fights the witches but cannot really bring himself to hate them.

The first unique romantic comedy manga in the history of CoroCoro! The slime he created transformed into a girl!? Kotarou, a young boy, is constantly pushed around by Puniru's freewheeling behavior. It's a fun and exciting daily life!

From classmates to brother and sister, living under the same roof.

After his father’s remarriage, Asamura Yuuta ends up getting a new stepsister, coincidentally the number one beauty of the school year, Ayase Saki. Having learned important values when it comes to man-woman relationships through the previous ones of their parents, they promise each other not to be too close, not to be too opposing, and to merely keep a vague and comfortable distance.

On one hand, Saki, who has worked in solitude for the sake of her family, doesn’t know how to properly rely on others, whereas Yuta is unsure of how to really treat her. Standing on fairly equal ground, these two slowly learn the comfortable sensation of living together.

Their relationship slowly evolves from being strangers the more the days pass. Eventually, this could end up in a story about love for all we know.

"I know! I'll destroy some humans to kill time!"

The strongest demon ever makes an unexpected appearance! But she's... a total airhead?! A comedy about a clumsy but emulous demon trying to kill time begins!

Author's Twitter: https://twitter.com/magoroku2

In a last attempt at peace, Clove, the last princess of a near-extinct Dragon clan is forced into a political marriage with an enemy prince.

From MangaHelpers:

This 4-koma comedy manga follows the daily life of the intelligent, responsible 6th grade elementary school student Haruna Raika. She keeps busy as the elementary student council president and the classroom leader, and she even fills in for the teacher sometimes! [tethysdust]

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4-Koma comedy following the super genius grade school student Haruna Raika and her every day life. Where she's the class president, the room leader, the top student, and even fills in for the teacher when they've overslept!

There are three female masters who are known to be the strongest in the world. The only thing they can’t get their hands on… their ideal man.

“If there are no ideal men, why not raise one yourself!?”

As they skim over the list of candidates, the ladies' eyes all fixate on one boy. A level 0 with no shred of talent…

Frey Raon Starlight was the hero who killed his family and comrades and destroyed the world. His goal was to return to the past, unlock a "hidden route" to truly save the world, and achieve peace.

As planned, he successfully returns to the past and gains access to the hidden route. However, his relief is short-lived as he is confronted with an unexpected truth: the five heroines he killed in his previous life have retained their memories and are now trying to kill him...!

Can Frey, under such extreme circumstances, save the world this time?

Duke Ferio Voleotti suddenly decided to adopt a daughter and finds a girl who he takes a liking to. This story is about a “loving” family of the world’s most richest, strongest, and arrogant father, his cute, blunt, muscle-loving adopted daughter, and a stepmother with a strange secret.

Takeru Kamishiro is an ordinary middle aged salaryman who was chosen by god to be reincarnated into a fantasy world in the body of a handsome young man in his prime with a very large penis.

A healer gets booted from his party because the leader notices he isn’t really contributing much to the team.

Soon enough, the healer must look for new members to party with. After finding a cute martial artist to work together with, he reveals his secret - while he’s a fairly mediocre healer, he actually fights well in close combat.

Anyway, here’s the story of a support who’s secretly a DPS, and where the entire conflict stems from the fact that he never told his old party he was DPS.

Kanae is a girl who is struggling to fit in with the popular clique at her high school. Because she had been bullied in middle school, she has developed an acute inferiority complex that had led her to engage in compensated dating in order to feel wanted.

In comes Hiroshi, a high-school baseball star who became drawn to her after finding her crying during a group date at a karaoke bar. Thus begins an unhealthy relationship between a mentally unstable high-school girl and a jock.

Suzuki Iruma has just been sold to a demon by his irresponsible parents! Surprisingly, the next thing he knows he's living with the demon and has been transferred into a school in the demon world. Thus begins the cowardly Iruma-kun's extraordinary school life among the otherworldly...

Jiang He, a girl from the Tang Dynasty, traveled through a thousand years and appeared in front of Xu Qing. Fate brought together this love that spanned a thousand years. Everything the girl was familiar with has become history. Relatives, friends, and enemies have all been left behind 1,200 years ago. The boy is unreserved and leads the girl to start a new life. Pain, confusion, cheers, and laughter will remain in this new world.

Takashi never graduated from elementary school because of not eating green peppers. He is already 20 years and his fellow classmate Megumi is a new teacher at his school. See how this story unfolds in a comedic way.

Ooyama-kun normally doesn’t get involved with Akutsu-san, a delinquent girl in his class, but for some reason she makes his house her hang-out place! Will Ooyama do something horrible to her behind closed doors or will he chase her out? But dealing with Akutsu-san’s sexy, cute behavior in such a confined space… he’s sure to get flustered! He wants her to go home, but he doesn’t? A teasing comedy under a single roof!

Note:
Yankee Musume (ヤンキー娘) is the pre-serialization name

Links:
Artist's Twitter: https://twitter.com/NAGAOKA0
Artist's Pixiv: https://www.pixiv.net/member.php?id=133935

One day, school teachers come as freeloaders to the inn run by his parents!? Kazami Hiro, a high school boy, decides to take care of the inn and his future!? Under one roof, The forbidden harem romantic comedy begins!!

In a certain place, there are two neighboring high schools. Chidori High School, a bottom-feeder boys' school where idiots gather, and Kikyo Girls' School, a well-established girls' school. Rintaro Tsumugi, a strong and quiet second year student at Chidori High School, meets Kaoruko Wakuri, a girl who comes as a customer while helping out at his family's cake shop. Rintaro feels comfortable spending time with Kaoruko, but she is a student at Kikyo Girls, a neighboring school that thoroughly dislikes Chidori High. This is the story of two people who are so close and yet so far apart.

Official Twitter (JA): https://twitter.com/kaoruhana_mp

Shunpei lives in a rural town of barely 3,000 people. Every day, he rides the same bus as his classmate An Takayagawa, the only one who went off to a private middle school. The two haven’t really talked since elementary school... until one day, something gives them a reason to.

A soft, sky-blue not-quite-love comedy, born on a bus for two.