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.

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".

Mikoto Rikudou, your average Secondary School kid, lives an ordinary life and doesn't think much about the unexplained appearances of figures called "demons" in the city. This is all turned upside-down when he finds the most timid girl in class is one of them, he is caught in the middle of a battle between these creatures and ends up becoming one himself… only to be told he will have to kill other people using his new powers or lose his own life instead.

Ten years ago, a young Jinta promised to marry a certain girl. And now that he's all grown up, a wacky oni girl shows up at his door! Get ready for a hilarious mononoke battle manga!

With his mother dying, Yuta attempts to capture her last days on his phone. After her death, Yuta heads to the roof of the hospital to commit suicide, but a meeting with a strange girl leads him on the path to making a movie.

A world where ‘Hexes’ exist. This is a story about a young Shaman and his companions saving the world from ‘Curses’.

Years after the end of Death Note… The legacy of Ryuk’s death note carries on!!

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!

Her everyday life has been suddenly soiled by blood and humiliation. Cheerful and popular high-school girl, Shibuya Mei was transfered to the other world and without knowing the reason why, she was eaten to death by monsters inside there. She felt every bit of "dying" in the other world and when she finally died, she found herself back in her world. It happened many, many times over and over again. She felt as if she was about to go crazy from the pain and sorrowful memories, when she met a boy - Akiba Yugami. He freed the girl from the chains of the virtual world she found herself in, but he wasn't so good as she thought he was. This is the story of a young girl fighting for her dignity.

Chuuta Kokonose is an orphan who lives with his aunt. For as long as he can remember he's had a voice in his head, but other than that he's been a normal boy—right until the day when a strange thing follows him home and teleports him to a place filled with even more fantastic creatures. It's a police station in space.

Surprisingly, Rein Brickke, the Chief of the Solar System Department, tells him that their computer chose him as a potential candidate for the solar-system's police force. However, Misuzu Sonokata, a girl from Chuuta's school with an angelic face and ill temper who turns out to be one of Rein Brickke's subordinates, doesn't think Chuuta is suitable for such a job.

Although Chuuta was shocked at first, he decides to take the aptitude test after being urged by the voice in his head. Most importantly, he wants to prove Misuzu wrong.

In a swimsuit, a bunny girl, and clothes that kill virgins.
A little naughty anthology comic of girls in various situations and costumes by 9 writers!

Shun, Kaname, and the twins Yuuki and Yuuta have been friends since kindergarten. It's a little hard to tell if they actually get along or not - but even as high-school students, they hang out together. Recently, they've had a new addition; a half-Japanese transfer student Chizuru, who has started to liven up the group. This manga is really just about their daily lives, which aren't particularly passionate or exciting. A tranquil and sometimes comedic story of youthful friendship.

Pocket Monsters stars a Pokémon Trainer named Red and his rude Clefairy. It is chiefly a gag manga, using crude humor and slapstick.
The series diverges somewhat from the Pokémon video game and anime canon: most Pokémon can speak human language and regular animals (like birds and fish) appear alongside Pokémon. Evolution is also significantly different in Pokémon Pocket Monsters: Pokémon can evolve at any time, and they are also able to reverse the evolution.
-Bulbapedia

In a world filled with talking Pokemon, Red and Green compete with each other in a race to gather all the data needed for the new Pokedex! Bumbling Clefairy frustrates Red with its extreme incompetence and silly behaviour... however, sometimes Clefairy's bizarre ideas to work out in the most surprising ways!!
-Chuang Yi

A story about a married couple who've abstained from sex until their wedding night. But on their wedding night, the wife turns into a little girl.

But that doesn't stop her from wanting children.

A Lovey dovey daily life with ara~ ara~ wife who can do time leap

Tokina is a self-proclaimed Timeleeper who loves to pamper her husband, Nobumichi. But today, there's something wrong with Nobumichi! While her husband accepts her sweet behavior without embarrassment, Tokina's flirting gradually escalates...?

Maa-chan's Diary is the first manga created by Tezuka Osamu. He authored it in 1946, and it ran in Shokokumin Shinbun (Mainichi Elementary Schoolchildren's Newspaper).

It follows the life of a little preschooler named Maa-chan, who lives in post-war Japan.

From Tokyopop:
After an imprisonment of five days in Heaven, which equals five years on Earth, Soma is sent to the human world to recover the lost sword. Under the supervision of the heavenly princess Aroomee, Soma must deal with the chaos that his deeds have produced.

This manga follows the adventures of a group of mercenaries: the barbarian Mocha (the main character), the rogue Buruman, and the mage Kiliman (Blue Mountain and Killie Mountain, respectively, are famous coffee brands in Japan).

Mocha and her gang belong to a dark mercenary guild. Mocha, being a barbarian, has great physical strength and, of course, she has no brain. Despite her very revealing suit, she is very innocent, pure and naive. The story starts when a light master seeks to hire some mercenaries, and the guild refuses to help him since he has no money with him. So the dark guild master sends Mocha, Buruman, and Kiliman to aid him. It's really not a great start but this is how everything begins.

The author's drawing dramatically improves after volume 5. The plot becomes much more refined as well. It can be considered a typical adventure story. However, this manga goes a little deeper than that.

After volume 10 or so, the plot becomes really profound and deep. Dragons are involved, and whole nations go to war. The scale becomes quite large. Really enjoyable manga.

After the great war of the late 1990s as Japan begins construction on a new capital city, earthquakes cause massive destruction and rumors of demons have begun to emerge. The protagonist receives a warning and a demon summoning program.

In the region of Kalos, an old tale spoke of two legendary Pokemon, Xerneas and Yveltal, who were said to appear every 1000 years to clash with each other. The myth became a reality when the two showed up inVaniville Town one day, wrecking havoc to everything in the area.With their homes destroyed, X, a prodigy in battling who went into seclusion after an incident related to to the paparazzi, was forced to go on a journey with his childhood friends: Y, a Sky Trainer in training; Trevor the scholar-to-be; Tierno the dancing expert; and Shauna, who aspired to become a Furfrou Stylist. Under the constant threat of the ominous Team Flare, who was after X's mysterious Mega Ring, the five young trainers must stick together and depend on each other to weather through each challege and seek what they find, including an answer to the mystery of Mega Evolution...