Toki wa… is a manga about two guys who travel back in time and visit Tokiwa Manor in the 1950′s. Tokiwa Manor is an apartment building where Osamu Tezuka, the father of modern manga / anime, and many other early influential mangaka once lived.

From MangaHelpers:
Ichijo Kazuya thought that he was murdered, but when he came to, he was back in his high school days. He lived his entire life as a playboy and had had countless sexual encounters with women until that fateful day that he was killed. He realizes that his murderer was his old high school friend Tanaka Masaki who was jealous of Kazuya’s relationships and his built up anger eventually exploded.
Taken back 15 years into his past, it seems that he has been given a second chance at life and given a chance to make different choices. He decides that the way to prevent his eventual demise is to make sure Masaki is more successful with girls and loses his virginity before Kazuya. But fate seems to be steering Kazuya towards the path of his previous life and keeps introducing the same girls he had sexual encounters with.

Fourteen-year-old Kouichi Hayase’s life has always been a mediocre one, if not dismal. However, those days of being bullied by classmates and escaping to a fantasy of being a hero are put to an end when a certain “accident” bestows on him a girl and a gigantic humanoid robot called “LINEBARREL”. The extraordinary power that Kouichi obtains puts him and everything around him on a sudden rollercoaster ride of battles, intrigues and friendship! During the course of his adventure, the boy starts to learn what life has to offer; he meets new friends, bids farewell to the old ones, but most of all he now has considerable responsibilities and is forced to confront the world around him.

One of Go Nagai's first works, this violent period piece takes place in the 1500s and stars a talented, low-ranking ninja named Shishimaru. In it, Shishimaru fights against Ginnai Doma (an immortal samurai who, despite being butchered multiple times, doesn't die) because Ginnai murdered his comrades.

Despite being set in historical times, it has time travel, aliens and the alternate universe war.

From MangaHelpers:
The world is in a war against an alien race called "Mimics," who have taken over most of the world with a mission to eliminate the human race. Keiji Kiriya is a new recruit in the United Defense Force, which is battling against these "Mimics." On his first day of deployment, Keiji and his unit encounter "Mimics" and are all killed... Or was it all a dream? For some inexplicable reason, after every time he dies, he is resurrected and returned back to the day before the battle. Why does this happen to Keiji and how can he escape from this never ending cycle?

Note: Nominated for the Eisner award for the "Best U.S. Edition of International Material - Asia" in 2015.

Feng Ming was only 19 when he lost his life saving a child from death without hesitation. The grateful father of the rescued child grants Feng Ming a second chance at life. Unknown to Feng Ming, his soul is whisked away to a far away ancient land (resembling the dynasties of China).
Upon waking up, he finds himself inhabiting the frail body of Thunder Kingdom's crowned prince who is also graced with the title of the most beautiful man across all the lands. However, his beauty has a price as he attracts the unwanted attention of the minister of affairs, Rong Tian who finds every reason to torment the prince mentally and physically. As Feng Ming starts to get a hold of the conspiracies surrounding him, what will happen when the prince's true identity is revealed? And what happened to the 'real' prince?

Junior high school student Yamada hates bothersome things like studying, eating, and bathing. When he discovers he can jump through time, would he be able to find the way to a perfect life?

From Anime News Network:

A collection of short stories that look to mankind's exploration of space, and examine the possibilities that we could face when we decide to take those first fateful steps into the unknown.

Fudou Jun is a highschool teacher and takes a trip with a group of students. While there, a group of martial artists staying nearby take a strange interest in the girls.
These men are actually demons and after changing into their true form break into the cabin to rape the girls. One gets Jun and violates her.
She feels her soul being torn apart and transforms into Devilman Lady. With newfound powers and strength she kills all the demons and protects the girls from any further harm.
What are these demons and why did she turn into a hybrid of one? What does this mean for her and for the rest of humanity?

"Doraemon" is a series about a robotic cat named Doraemon, who travels back in time from the 22nd century to help a schoolboy named Nobita Nobi. Aside from the normal manga books, their great adventures to different places are specially described in Doraemon Long Stories books.

1. Volume 1: Nobita's Dinosaur
Nobita found a huge stone which he sure was a dinosaur egg. It seemed highly unlikely, but it did turn out as a dinosaur egg. That's when he and his friends go back to the past to the dinosaurs era.

2. Volume 2: Nobita's Record Of Spaceblazer
Nobita no Uchuu Kaitakushi
Nobita and friends tried to find a whole new planet because they can no longer play on the baseball field. They did find a new planet somehow, and big surprise: they become super humans with super power in that planet!

3. Volume 3: Nobita & The Haunts Of Ghost
Nobita and the gang were Itching for an adventurous expedition. A seemingly stray dog came to them and guide them to one.

4. Volume 4: Nobita's Monstrous Underwater Castle
What if you can live and breathe in water? An under-the-sea adventure!

5. Volume 5: Nobita's Great Adventure Into The Underworld
Nobita thought a world with magic would simplify everything, including housework. When he finally got his wish granted, magic not only come with fun stuff but also some demons and evils as well.

6. Volume 6: Nobita's Little Star Wars
Adventure involving mini-sized aliens.

7. Volume 7: Nobita & The Steel Troops
Robots overthrown human's civilization! Not if Doraemon and friends can help it.

8. Volume 8: Nobita & The Knights of Dinosaurs
Nobita wanted to find a place to hide his 0 mark test papers and they found a hole that is far bigger than what they can ever imagine.

9. Volume 9: Nobita's Birth Of Japan
They all return to the past where human wasn't yet exist and start setting up a home/ play ground. Little did they know there was already civilization in that era. That, plus a wicked mage.

10. Volume 10: Nobita & The Animal Planet
A planet whose inhabitants are animal-human gets connected somehow to Nobita's house. Where do they come from and who does Giant and Suneo meet when they go there?

11. Volume 11: Nobita's Dorabian Nights
The Arabian Night. Is it just a story, or is there any similarity with an actual time frame? Nobita and Doraemon explores with the rest eventually caught in the process.

12. Volume 12: Nobita & The Kingdom Of Clouds
Does heaven exist? Nobita was laughed at when he stated it does exist. So Doraemon created a kingdom on the clouds, invisible from outside; only for them to eventually find others that already existed.

13. Volume 13: Nobita & Tin-Plate Labyrinth
A holiday at a place where everything is made by nothing but tins brought them to another adventure with tin robots.

14. Volume 14: Nobita & The Fantastic 3 Musketeers
Nobita wants a good dream where he becomes a hero who will save a kingdom from evil and gets married to the princess as a reward. But how real is the dream world?

15. Volume 15: Nobita's Genesis Diary
Nobita's summer holiday project brought him to a world of insects.

16. Volume 16: Nobita & Galactic Express
A ticket to a train that travels between galaxies becomes a ticket to adventure against aliens.

17. Volume 17: Nobita's Adventure In Clockwork City

18. Volume 18: Nobita’s South Sea Great Adventure

19. Volume 19: Nobita’s Drifts In The Universe

20. Volume 20: Nobita’s Legend Of The Sun King

21. Volume 21: Nobita & The Winged Braves

22. Volume 22: Nobita & The Robot Kingdom

23. Volume 23: Nobita & The Wind Wizard

24. Volume 24: Nobita’s Wannyan Space Time Odyssey
Eiga Doraemon: Nobita no Wannyan Jikuudenden

Fear runs rampant throughout Tokyo with the revelation that demons in fact exist amongst us. Paranoia and the darker side of humanity boils onto the streets as people turn on one another, suspecting that anyone could in fact be a demon hiding in human clothing. Amidst the growing tensions, tragedy strikes Akira causing his mind to snap, retreating into his subconscious, allowing his Devilish alter-ego Amon to break free from Akira's cage of flesh and wreak havoc on both human and demons alike.

Ryo and Akira travel through time in order to eradicate demons that could have changed history. Various periods are visited: from pre-WWII to ancient Greece, middle ages in France meeting Joan of Arc, far-west America, renaissance.

It is the year 1999. In Nagano Matsushiro stands the pyramid of Japan, the private Voltstein Academy.

This place is famous for repeated occurrences of occult phenomena within its premises. Hence, it is also called the Occult Academy. The dean is committed to studying the occult, while the students are zealous in their everyday schoolwork.

One day, the dean passes away and his occult-hating daughter, Kumashiro Maya, visits the academy. There, she meets a self-proclaimed spoon-bending "time agent" from the year 2012, Uchida Fumiaki. As the two encounter various bizarre phenomena within the academy, the reason for Fumiaki's timeslip to 1999 becomes clear.

Houjou Hinaki is a young girl who has in her possesion a ring, a gift from her father. Anyway, this ring is not an usual one. When she kisses it, a young noble man named Sae appears in front of her and grants all her wishes. However, Sae is trapped in the ring and can't tolerate much time outside and together with Hinaki and her freaky schoolmate Yume-senpai, tries to find out a way of how he can escape from the ring's prison.

Kagome is a modern Japanese high-school girl. Never the type to believe in myths and legends, her world view dramatically changes when, one day, she's pulled out of her own time and into another! There, in Japan's ancient past, Kagome discovers more than a few of those dusty old legends are true, and that her destiny is linked to one legendary creature in particular--the dog-like half-demon called Inuyasha! That same trick of fate also ties them both to the Shikon Jewel, or "Jewel of Four Souls." But demons beware...the smallest shard of the Shikon Jewel can give the user unimaginable power.

Won the 47th Shogakukan Manga Award in the Shounen category.

Following the Tuatha de Danaan's seajacking incident, things are back to normal at Jindai High School in Tokyo, or as normal as they get with Sousuke guarding Kaname. After finding out who betrayed Mithril and caused the seajacking incident, Kurz and Mao are sent on a top secret mission in order to capture and bring the traitor back.

However, Sousuke and Kaname's lives are about to change when they meet Leonard Testarossa, a high ranking member of a mysterious group named Amalgam. After their meeting, Leonard warns her that he would do anything to recruit her even if it means war in the streets of Tokyo.

From Yen Press:
The air of celebration surrounding fifteen-year-old Oz Vessalius’s coming-of-age ceremony quickly turns to horror when he is condemned for a sin about which he knows nothing. He is thrown into an eternal prison known as the Abyss, from which there is no escape. There, he meets a young girl named Alice, who is not what she seems. Now that the relentless cogs of fate have begun to turn, will they lead only to crushing despair for Oz, or is there some shred of hope for him to grasp on to?

Dragon Ball follows the adventures of Goku from his childhood through adulthood as he trains in martial arts and explores the world in search of the seven mystical orbs known as the Dragon Balls, which can summon a wish-granting dragon when gathered. Along his journey, Goku makes several friends and battles a wide variety of villains, many of whom also seek the Dragon Balls for their own desires. Along the way becoming the strongest warrior in the universe.

Three students battle sadistic professors, annoying roommates and evil conspiracies at a second-rate university for superheroes. A French comic with heavy stylistic influences from American comics and Japanese manga, and tons of pop culture references.

From Anime News Network:
The story begins in the distant future in the far reaches of the galaxy. The Human Galactic Alliance has been constantly fighting for its survival against a grotesque race of beings called "Hidiaazu." During an intense battle, the young lieutenant Ledo and his humanoid mobile weapon Chamber are swallowed up into a distortion of time and space.
Waking from his artificially induced hibernation, Ledo realizes that he has arrived on Earth, the planet on the lost frontier. On this planet that was completely flooded by the seas, people live in fleets of giant ships, salvaging relics from the seas' depths in order to survive. Ledo arrives on one of the fleets called Gargantia. With no knowledge of the planet's history or culture, he is forced to live alongside Amy, a 15-year-old girl who serves as a messenger aboard the Gargantia fleet. To Ledo, who has lived a life where he knows nothing but fighting, these days of peace continue to surprise him.