After Rimuru's encounter with Shizu-san in the manga, he learns how to mimic a human form. However, the body...was that of a three-year-old child!? With chibi-Rimuru and his friends unleashed from the Great Forest of Jura, maternal instincts hit in the “Tensei Shitara Slime Datta Ken” Official 3rd Spin-Off!

I confessed. I couldn't do it while sober so I took a shot of liquid courage.

“I like you.”
“Why?”
“I just like everything about you.”
“... I don't understand.”

Something's strange. His voice is deeper, his height slightly different, and his physique even more so. In fact, after a closer look, even the hair colour that reflected the moonlight⁠—this is crazy. It’s someone else. It's none other than Duke Cabel Willard who's known as the 'Grim Reaper' of the battlefields.

“Cabel.”
“... Excuse me?”
“From now on, don't refer to me by any strange titles. Call me by name instead.”

The corners of his lips that were always frozen stiff curved into a smile. It seemed like he would immediately kill me if the truth of my false confession was brought to light.
Official Chinese Translation: https://www.kuaikanmanhua.com/web/topic/5965/

The stoy of an elf queen who got isekai'd from her world into our world. Her name is Lady Elfinn, our titular queen.
And a sweet boy who believes in the Elf supremacy. His name is Isuzu.
Their fates clash after Isuzu gets assigned to take care of Elfinn, and help her accomplish her task: To become the queen of the human world and to guide us into a better future.
In order to help her with their final goal he proposes...

To master the old ways of the S&M to conquer the world!?
What awaits them in the future!!??

Guy reincarnates into the gardening apprentice who works for the rival character of the heroine of an otome game.
He doesn't care and just wants to be a gardener.

Original Novel: https://ncode.syosetu.com/n1313ff/

The great sage, Grameos, tired of his current life as a famous mage, decided to reincarnate as a young boy 200 years in the future. Before reincarnating, he places two magic restraint seals on his hands, so that he can hide his enormous magical power after he is reborn. His motto for the next life is "Hide my powers, don't stand out, and be free".

The Greatest Mage, Princess Leticiel, lost her life in a war and transmigrated a thousand years into the future. Angered by the regression of “Magecraft” in that world, Leticiel set out to develop it, much to her surroundings’ dismay. However, her actions would soon get her and the people she knew involved in a certain plot…

Satou Shiki, a university student, was suddenly stabbed by a slasher only to be reincarnated in Labyrinth City. In this other world, he who has awakened to [Appraisal] and [Healing Magic] does a lot of “things”.

42 year old “shachiku” (company slave) Matsuda Takeshi gets worked to death, as is customary in Japan. His one dying wish is to work for a decent enterprise, not the black company he had been working for. His wish is heard by a god who, for his own amusement, has him reincarnate as a young elf male in another world, with increased affinity for earth magic and ability to command golems. The new golem master sets out on a quest to acquire the Seven Treasures left behind by a legendary mage from 1000 years ago.

I am Owen Pepper, the heir of a Noble family. To begin with, there are two kinds of people in this world. The aristocracy, winners from birth, and the rest of the losers, the cattle. I am a winner, of course. Bwahahaha. Livestock, you can work hard for me today. It is the only thing you lot are good for! I have been reincarnated as a tr*sh aristocrat. My father was a villainous lord. And his son, Owen, has been deeply influenced by his father and has grown up to be a fat, incompetent boy! If this continues, my future is in jeopardy. … But I do not care about that! “I heard that there is magic in this world. If we are going to go to all this trouble, let us try to master magic!” And if you are having fun learning magic, you will soon be able to break the stigma!
(taken of NovelUpdates)

The beautiful lady, Louise, has memories from her past lives. And there are 7 peoples' worth of lives (moreover the villain's role). Louise, who has always met the bad end of getting stabbed to death, has decided that she will live this life peacefully. However, Louise has been assigned as Prince Emile's instructor! And so, she struggles with teaching the extremely shy prince who shuts himself up in his room. In her 8th reincarnated life, she will do anything for a happy ending!

Exploring the mysteries of the reincarnations and the secrets behind her previous deaths, this is a high tension comedy with the reincarnated lady and unique characters!

After dying in a traffic accident, I find myself standing near an unfamiliar lake. My body won't move, I can't hear my voice, and when I try to shout in confusion, words that I never expected come out!"Get one free with a winner."I-it seems I've turned into a vending machine...! I can only do what actual vending machines can. It's impossible to move by myself, and there's no way for me to have any meaningful conversation-how am I going to survive some fantasy world's dungeon like this?!

(Source: Yen Press)

Ars, the prince of the Kingdom of Karitz, who was called the strongest wizard, died at a young age. But on the verge of death, he uses reincarnation magic. Reincarnated as Wals Sai, a slave with the best body! Wals, who became the escort of a princess in a small country, became a matchless slave who used his best body and magic to crush all enemies! From "Become a Novelist"! A fantasy adventure by "the strongest slave", opening !! * "Become a novelist" is a registered trademark of Hina Project Co., Ltd.

Huang Bei Yue is an assassin that gets transported to another world thanks to a mysterious jade, boundless beast!
Now she resides in the body of a 12 year old, who happens to be the king's sister, who is constantly bullied!
"Now how shall i take my revenge?"
Original Webcomic (Chinese)

One day, Yadoya Kenta, who was working for a black company, dies of exhaustion. When he wakes up, he finds that he has been reincarnated not as a hero in another world, but as Tohri, the son of an innkeeper in a rural town! This time, he wants to work moderately and relax! Surrounded by a kind family and lively customers, the slow life of an innkeeper's son begins!

Lise, a knight and daughter of a baron of the Kingdom of Olwen, lost her life protecting the young imperial prince Egbert. After death, she wakes up in the future with all her memories! But somehow she’s become engaged to the imperial prince?

The story of a (Former) Lady Knight… trying to dissolve her engagement?!

A romantic comedy about a reborn Court Lady with a secret!

"To pass time before surgery, Hwayoon read a romantic novel for some steamy scenes.

Little did she know this would lead to her reincarnating into the story as an insignificant maid that's executed soon after. The goal is to survive, but things get out of hand... and steamy.

[Tensura] spin-off new serialization launched!! When I woke up, the slime figure was still the same salaryman as before!? Moreover, Benimaru, Shuna, everyone's here and I'm the section chief! Rimuru's middle manager's life begins without knowing the cause of it all!!

Yunife Magnolia, a villainess friend of the heroine in this novel called Rael Cania.

The Yunife inside the novel has always loved the male lead, Ishid. To the point where she harassed Rael out of jealousy because she's loved by Ishid.

And thus, Yunife is destinied to die in the hands of the male lead of this novel.

But one day,

"Why did I become Yunife?!"

But let's think about it, it's still one year away from the time Yunife is going to get killed by Ishid. So, I have to meet Ishid and Rael first, I'll be able to find a way out of my death if I do so.

Yeah, let's meet them first!

But, this man is just so tender-hearted and kind. Would Junipe be able to escape from this man?!
this...???

After the war, there are many "Extends" in the city, people whose bodies were modified to make them into dangerous weapons. Inui Juuzou is one of them, and he has no memories of his life and body before his head was transformed into a gun. Strangely enough, his head-gun is designed so that only someone behind him can pull the trigger. Juuzou makes a living by taking on cases involving Extends in the city, and he is assisted by Mary, an intelligent young woman that he has taken under his protection.

From Sunflower Scans:

A man whose time has stopped, and a woman who flows like a river.
Story about strife that comes and goes in the past and in the present.