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...

Hinata is an introverted geek who sits next to Mikage, a gal, in class. Hinata realizes that Mikage is a former friend from elementary school, and attempts to rekindle their friendship.

Amy is an ordinary girl who lives with her beloved father. However, she is not human, but a doll made up of cloth and cotton. Why was she created, and what does her future hold?

Han Qingyu lived peacefully for nineteen years, and never thought that one day he would become one of the main characters in an epic. An accident occurred out of the blue. The boy was forced wield a knife and began to face everything he knew nothing about: the invasion of civilization, the Azure Alliance, the mobile energy suit, the unique witness corps; the blade of exile, the sharp streams... He is narrow-minded, he is "The Qing Major" painted on cars and high-rise buildings in the era of full-scale military conscription; he will make the first cut in the Zenith War.

The space ship "Leviathan" was once the arena for a cruel battle of survival. The only hope: a cryogenic chamber - but there's only room for one person

Old-school Ani × Modern-day Imouto, paving the road ahead for a new manga!

Midorimaru Matsunoki, the only son of lord Matsunoki Mumeharu, retainer of Hideyoshi Toyotomi, becomes involved in his father's secret plans about construction of a new castle. Soon after encounters a female peasant school teacher, Tae, who becomes his lover. Circumstances even come to affect the beautiful female noble Yayoi, who hates (and loves) him, and his beloved sensei, samurai Fujinosuke Murasaki, the main constructer of the castle, in ways no one would have anticipated...

This is a fast-paced story with overt characterization that reflects on the fairness of love and war.

The manga that made Tezuka famous. It is an action-adventure drama inspired by Robert Louis Stevenson's book.
One day a boy named Pete finds a map of "Treasure Island" that his deceased father left behind. He starts on a voyage to find it together with "Captain," who was a friend of his father. But his ship is attacked by pirates, led by Bowarl, and the two are caught. When a storm hits the pirate ship, the two are thrown into the sea and washed up on the shore of a solitary island in the southern ocean. To their surprise, this island is the one they have been looking for....
The Western-style art and fast-paced storyline attracted much attention, and it became a best seller with 400,000 copies sold, laying the groundwork for the manga craze and its modern style.
The original version of "New Treasure Island" was based on Tezuka Osamu's manuscript, but substantial modifications were made by Sasaki Shichima, who cut nearly 60 pages and also changed some of the lines. When publishing "The Complete Works of Tezuka Osamu," Tezuka Osamu remade it based on his memory to make it closer to his original.

Kenzaki Ryuunosuke is a new editor for Weekly Shounen Magazine, but his love for an unpopular series gets him no love with his coworkers. He meets Takanashi Tsubasa, an aspiring mangaka, and seeks to prove himself by making her the number one manga artist in Japan.

A heartwarming romcom about a boy who can't help but want to punch girls and the heroines.

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)

This is the story of five students who make up a crazy and unique group (the gang of the funny faces) and, in an incredible twist of luck, they befriend the cutest girl in school. Of course, they will enter into competition with many groups in their school, where teachers are tricky and sometimes clueless, where they can still defy the laws of nature to win sports tournaments and where you can still be childish, Anything could happen in this high school.

Long, long ago, humans lived almost the same as beasts... If you got hungry, you could just find something to kill and eat it. If someone attacked you, kill them too. Everything was kill to survive, kill to survive. Then people started acting smart and making laws. The laws kept them from doing pretty much everything they wanted to do. Beasts, on the other hand, still have no laws, or etiquette. I predict the day will come when an almost mutant breed of humans will appear, sinking to the level of beasts for freedom... Here, I will call them "Vampires..."

Kuon Otogami was a genius pianist whose name is among the greatest in the annals of the music world. He had seven children who also all became genius pianists. All seven except for the one named Lucky that is. This is the miraculous story of a regular kid taking on godly talent!

Jumonji sits next to a rapper girl who is also anti-social... what will they do to realize her dream of becoming a real rapper?

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.