In the tough times after the Japanese economic bubble burst, a career woman suffering through the aftermath reincarnates as Keikain Runa, the villainess of an otome game with a modern setting! However, not long after reincarnating, she realizes just how dire a situation her family is in due to the ongoing financial recession. Using knowledge from her previous life, Runa sets out to rescue her new family from crisis and stand against the tide of 'the times' that caused her past life to end in misery.

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.

It killed the heroes, killed the king, the devil beast then found the “baby of fate”…
Having both superior intellect and destructive power, such is Clevatess, the king of the devil beasts.
Angered by the 13 heroes tasked to take his life, he decided to bring ruin on mankind but get entrusted with an unexpected nuisance: a newborn human baby.
Is it the tale of a near-ending world close to the apocalypse or the diary of new era childcare?

Mikhail Walpurgis, the world’s only 9th-circle Archmage, fell in battle due to a damned hero, and managed to cast one final advanced magic spell, [TIME REVERSAL]. As time rewound, he regressed to 20 years ago.

“Fine. I’ll just become the hero instead.”

In a politically arranged marriage devoid of love, Lily is wed to Theodore, the head of a rival family. Theodore loathes the union, but little does he know that Lily despises her own family as much as he does. Living a quiet life, she counts the days until their inevitable divorce. Then fate intervenes—a sudden accident erases Theodore’s memories of her, transforming his coldness into unexpected affection. Can Lily trust this dramatic shift, or must she guard her heart to avoid future heartbreak?

From Transcendence:
Long ago, there existed a land divided into four countries: Sou, Kou, Do, and Ah.
The King of Ah took on a wife from Kou and soon thereafter one from Do, creating a shaky alliance between the three nations. When the Second Queen gave birth to a son, the King cast aside the sickly First Queen and her daughter Aki into the depths of the Palace. But as Fate would have it, Princess Aki encounters a slave named Hakusei, who has peculiar golden hair and sky blue eyes. He promises his life to her and helps her train in the Six Arts under the guidance of the enigmatic merchant Seitetsu. However, when Aki outshines the Prince during a hunt in an attempt to gain her father's acknowledgement, she sparks a war by besmirching Do's honor and drives the Second Queen to poison her mother.
With nothing left but her faithful Hakusei, Aki is banished to the small country of Kou with a vow to return to Ah one day for revenge. But in the face of the mighty allied nations of Do and Ah, will the two survive long enough to carry out Aki´s vow?

Note: Won the 60th Shogakukan Manga Awards for Best Shoujo in 2015.

High school student Boji Nichiro is isolated from the rest of the world due to fierce bullying. One day, however, the world is transformed by the "dungeonisation" phenomenon! In the midst of the chaos, Nichiro awakens the unique skill "Shop". It was an out-of-the-box skill that allowed him to buy everything from food and daily necessities to unrealistic items! The start of a painful and "wacky" modern fantasy from "Shosetsu-kaerou"!

After tomboy Haedam is thoroughly friend zoned by her first love, she's determined to glow up before college. But when she makes the wrong impression on her first day of school, she realizes she needs the help of her reluctant neighbor. In exchange, she promises to put up with their living circumstances and keep his secret. What could possibly go wrong?

A town in ancient China has fallen under a curse and all the water resources are drying up. In order to save everyone, a young girl has been picked as a sacrificial lamb for the water God Kahaku, who resides in a far away places called Suiko. The girl and his bodyguard En travels to Kahaku to prepare for her sacrifice, however, everything is not what it seems.

A story about a man who wants to make a zoo full of mythological creatures in isekai.

An empire stained with blood

That day, consumed by the cursed sword, I cut down the people I loved most with my own hands.

Fifteen years have passed under its curse. Now, having claimed all ten legendary swords forged by man, I made a wish upon the holy sword.

"Take me back—to the time I killed anyone."

Time rewound to the moment before all tragedies began. And yet, the sword remained in my hand.

This time, I won't succumb in the same way. Neither the cursed sword, nor fate, nor anyone else will control me again.

"There won't be a second miracle.
This time, I will find happiness."

Remake of Eko Eko Azaraku.

The original manga focuses on high school student Misa, a model student who is also secretly a witch who uses brutal dark magic to fight for justice.

From MangaHelpers:

After being kicked out of the main dorms for bringing in a stray cat, Kanda Sorata is forced to live in the smaller Sakura Halls where problem students are sent to live. Although he doesn?t mind his roommates, Sorata can?t wait to move out of Sakura Halls. But when Shiina Mashiro moves into the dorm, everything changes. Mashiro is an artistic genius who, at a young age, won many awards for her skills, but due to her childhood being so focused on art, she has no common sense and social skills. Forced to take the role of taking care of Mashiro, Sorata learns about himself and begins on a path of self improvement.

College student Seiji Kitou and his friends go to an abandoned building as a test of courage, and meet an attractive woman who is a monster that swiftly kills and eats people as soon as she meets them. While trying to escape, Seiji is saved by a mysterious woman with the same ability, Kiri.

I'm done with romance, so send me home!

Kim Yi-Young was just an ordinary civil service exam candidate in South Korea.
After studying for more than four and a half years, she finally passed, a truly ordinary person with nothing but reading novels here and there as a hobby.

However, on the day she went out for a celebratory meal after passing the exam, she got into a traffic accident and died, only to find herself reincarnated into the fantasy hunter novel she was reading.

To her, the "System" offered a way back home.
Determined solely to return home and cuddle her warm cat and adorable Maltese, Cerberus, she gained strength through dozens of regressions.
Signing contracts with the constellations of the original work and dying multiple times, she eventually succeeded in conquering the "Tower" of the original work and defeating the owner of the tower on the final floor.

Now, all that's left is to go home......

Or so she thought!

[Due to an error, instead of returning to the original world, we will reincarnate you into the author's new work!]

I don't need that! All I wanted was my sweet home!
Is that so difficult?! I even got rid of the Tower!?!?!

Moreover, romance fantasy?! Even in my previous life, I didn't care about romance, not one bit!
And to top it off, I didn't even reincarnate into my own body this time, but into the "villainess" of the book!

I'm not afraid of the threats in this world, but I'm worried about being forced into a romance quest.

Can I go home......?

The purported advertisement from the Jump Square issue says that everything in The Prince of Tennis up to now has been a "prologue" and that "a new legend for Ryoma and the others will begin."
50 middle school players have been invited to participate in the All Japan U-17 Selection Camp. Ryoma Echizen returns from the U.S to join his teammates and rivals.

Ryouma Takuma, a 39-year-old man with a hidden past, finds himself in a strange white room. The gods tell him that he has died and they are sending his soul to a different world, a world where magic exists. Living alone for 3 years, his gamer soul loses common sense and starts heading toward crazy routes.

"Hey, boyfriend, how you doing?"

Souta Sakuhara is a first-year high school boy. His first ever girlfriend has just been stolen away from him by a "girlfriend." That girlfriend is Shizuno Mizushima, a tomboy who's also the tallest girl he's ever met, who's now his hated rival in love, taunting him with it. But then…

"Since nobody else wants to be your girlfriend, how about you go out with me?"

She suddenly pins him against the wall! She also started saying, "Give me a month, and I'll make you fall in love with me…… I'm not going to let you go so easily!"

A one-way romantic comedy in which a handsome and beautiful girl will tempt you every day!

The events chronicled in this manga are also depicted in its own campaign in the Gundam: Meguriai Sora game for Playstation 2 (released in the US as Gundam: Encounters in Space), as well as a novel by Kazuki Miyamoto.

Some of the characters are seen briefly in Mobile Suit Gundam - Lost War Chronicles manga.

Note: A masterpiece collection titled Kidou Senshi Gundam Gaiden - (Uchuu) Sora, Senku no Hate ni... was release in 2015.

I suddenly remembered. This world is the world of an erotic manga, and that I was reincarnated as the scumbag who is supposed to steal the heroine in this world. Well, I don't have such a hobby, so I thought the heroine should get along with the protagonist. But why are you paying attention to me, heroine?