An introverted Otaku was summoned to a Fantasy world, and successfully defeated the Demon King there. Just before the ritual to send him back to Japan was complete, the country's Princess dashed into the middle of the spell to be with him.

When they both opened their eyes, they realized they were transported to a Sci-Fi themed world than neither of them recognized. Working together, they must now survive in an unknown world and find some way to get home.

I’ve been reincarnated into a world of strategic gaming where I acquired number 1 Rank!

I thought I would be reincarnated as a warrior in a gaming world that I know of, but I found myself to be a rogue lord who dies in the prologue! And I only have one day left before I die due to another country’s invasion..!

Use all your wits, courage, and gaming knowledge to face your destiny!

It’s a strategic fantasy where you risk your life to turn the tables!

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)

From MangaHelpers:
Sagara Soma is a hardcore gamer, who spends basically all of his time playing or thinking about games. Since he was a child, he's thought of how great it would be to really live in a game world. One day, when he breaks a promise to his cousin Maki in order to play video games, his wish comes true. "New Communicate Online," also known as "Neko-Mimi-Neko," is the game he was playing at the time. Neko-Mimi-Neko is well known for its trick quests, occasional unfairly high level enemies, and many bugs, all of which combine to make players die over and over again. Now that Soma seems to literally be a starting character in the game world, will he re-spawn after death, or actually die? Luckily, he knows just about everything there is to know about the world of Neko-Mimi-Neko, so he may be able to make the unfairness in the game work to his advantage.

From Yen Press:
After being soundly thrashed by the hero Emilia, the Devil King and his general beat a hasty retreat to a parallel universe…only to land plop in the middle of bustling, modern-day Tokyo! Lacking the magic necessary to return home, the two are forced to assume human identities and live average human lives until they can find a better solution. And to make ends meet, Satan finds gainful employment at a nearby fast food joint! With his devilish mind set on working his way up the management food chain, what will become of his thirst for conquest?

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!

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)

Yukino Amaishi signed a contract with God to save her sister. She was then reborn in a different world as Lefina Eilferia, the daughter of a duke and the Crown Prince's fiancée. After successfully completing the objective of giving the heroine and the prince a happy end, Lefina, who played the role of the villainess, ends up working in the castle as a maid.

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!

When playing a virtual reality game called Cang Lan, Xiao Wan gets pushed off a cliff. She ends up in another game world. What will happen to Xiao Wan?

Office Lady falls from a building is reincarnated into another world and ends up at the Devil Kings castle. Can she save him from the bad ending?

In the year 672 of New Era, the much-revered stylist and sovereign King Sayet passed away, leaving three great outfits known as his “legacies” behind.

So great were his treasures that it divided the nations and plunged them towards a bloody future plagued with war. The nations desperate to avoid war, not wanting to ravage their lands, managed to agree to settle the matter using a styling contests for ownership of Sayet's treasures.

This styling contest was far more intense than anyone could have imagined, having lasted as long as 9 days, and being remembered in history as the “Nine-Day War”.

Eight years later, the war is over and peace has been established between the nations. However, things are not what they seem, and the wind of war has started to blow again.

Nikki, a normal girl from earth is summoned to this new world of stylist know as Miraland, as she may be Miralands' last hope to shift the course of the land's fate.

The comedy spin-off story focuses on the Spear Hero, Motoyasu Kitamura. At the brink of death he acquires the power to turn back time, and decides that he'll use it to become stronger and start a "new game."

"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.

Souhei embarks on a trip in the gigantic labyrinth that suddenly appears in his basement. But it's an extremely special dungeon where the only way to become stronger is to do lewd things with girls and increase Lv (Love)! The story of a young boy who explores and does lewd things with women!

One day home from work, the exhausted salaryman Amano's bathtime is interrupted by an elf suddenly emerging from the tub! This clumsy but kind of brilliant (direct quote) otherwordly elf comes to the human world to take it easy and enjoy reading some manga.

In the year 20XX, Japan began exchanging ideas and cultures with other worlds. One day, a beautiful elf moves into the apartment next to Keita Inudo, a high school boy who aspires to be a Mangaka. But she won't be the only girl to push herself into Keita's daily life! Will he be able to cope with all these sudden appearances while keeping his home, his career aspirations, and his sanity intact?

Even though humanity loathed him just because he is ugly, Hero Garius still did everything he could for them.
However, after they double-crossed him, he finally had enough of humanity.
And now, he has decided to save the demon world because he finally found the warmth that he longed for in the demons' instead!!