It's New Year's Eve, and there's a countdown party at the luxury hotel, Babel. Kouta, a new hotel employee who's dissatisfied with his own status quo, finds his fate forever changed following an encounter with two mysterious guests: Ozaki and Naomi.

On New Year's Day, he bears witness to a world-changing event. And with The Babel as his stage, navigating a complex web of human relations, Kouta's mission begins!

Mitsuhiko Amano is full of regrets. A 46 year old salariman who had just been laid off, he was told that his wife wanted a divorce, something that he might have been wanting for years. So he visits a soapland, a place he hasn't been since he started dating his wife 22 years ago. While there, a fire suddenly erupts, trapping Amano and a soapland girl in the bath. In a rare moment of bravery and decisiveness, Amano attempts to lead the girl to safety, only to slip and hit his head. As his consciousness fades, he sees the back of the soapland girl making her escape... A fresh set of regret blankets him as he passes out, that his wife Sachiko and daughter Miyu will be objects of ridicule that he died in such a place...

Then he awakens. In front of him is Ozawa Satsuki, a girl he hardly knew but secretly liked in high school. And Takahasi. Nakao-san, and Iijima-kun too. All his high school friends in their high school uniform, in their, and his, old high school... He has slipped 30 years into his past.

Has he been given a second chance? To change his life so that the regrets that weighed him down never happen this time around?

Six men and women are reunited at a high school reunion. Our heroine Tamaki meets her first love again, which was unrequited, nine years after graduating high school. The next day she wakes up to find she has time-slipped 10 years into the past and is once again a 17-year-old?

A love story of redoing your youth!

Yuri, a modern day teenager who had just received her first kiss, is suddenly whisked away to ancient Anatolia where an evil queen wants her for a blood sacrifice. Luckily, the timely intervention of Prince Kail saves Yuri from the queen's grasp. For now. Kail promises to send Yuri back to her home, but the queen's persistent schemes to kill them both, plus their growing interest in each other, keep those plans delayed.

Note: Contains a side story called Orontes Renka that is published in the final volume (28) of Anatolia Story, which is set in the same historic period.

In 2001 this series won the Shogakukan Manga Award for shoujo.

The story follows a super heroine who stepped back and retired a decade ago. She withdrew to a humble life as a homemaker with her daughter. However, her beloved daughter was selected to become the next-generation heroine, so she returns to protect her daughter.

Note: Tamaki Nozomu also draws 2 hentai doujinshi sequels series.

From Hoshikuzuu Scans & Rooftop Love BL : -

We have Amemori, who claims that he has always been having psychic dreams about Yui falling in love with him. And then we have Yui, who kisses him on the exact day that was in the dream. So is their love some psychic fate?!

From Forbidden Garden

Midori moves from Tokyo to start her senior year of high school in Sendai. She saved her childhood friend Aa-chan from teasing, but the class boss, Erena, stirs up a revolt and makes her the new target. Midori can’t bear the never-ending torment and personally takes her own life. Midori gets a second chance at life, choices and revenge though. This is Momochi Reiko’s first challenge at a time warp story!!!

This award-winning classic story focuses on Marlee, an agent of the space empire sent on a mission to track down the opera singer Eroccus. There are three intertwining narratives which span planets and hurl the readers back 30,000 years in time. The narrative takes place in a non-linear fashion, unfolding across space and time, before folding back upon itself at its culmination.

Note: Winner of the Seiun Award in 1983.

Note 2: Gin no Sankaku was not serialized in a manga magazine. Based on content, it could be considered either seinen or josei.

A military test accidentally sends a modern-day army back in time to feudal Japan. When their actions in the past begin to have an effect on the present, another unit is dispatched to retrieve them. But the commander of the lost unit has other plans. He intends to use his advanced technology to conquer Japan and change his country's destiny. -- {Summary by Mangaupdates.com}

This is Shotaro Ishinomori's manga adaptation of Shozo Numa's seminal S&M science fiction epic.

Volume 11 : Time Travel & Time Travelers1. A Watch Seller Travels Through Time by Takayama Shinobu*2. The Classroom Where He Is by Kumeta Natsuo3. The Person from the Future is Next to You by Mikawa Verno4. Time Travel by Gunjou5. The Professor and the Strange Love and Hate by Saeki Yashiro6. Samurais by Kari Erika7. Mushroom and Kappa - Time Travel Chapter by Magami Guriko8. Memento Mori by Tokitoh Kanade9. Darkness Future Design by Yoneyama Setsuko10. You Can’t Travel Through Dimensions by Kinoshita Sakura*11. If Time... by Buchi Keiko12. Nankai Loop? by Serikawa Mame13. Future Tedium Efforts Record by Mitsu Nanae14. When I Came Home, There was a Samurai by Igarashi Ran15. After Long Long Years by Sakura Maro* indicates oneshot being scanlated.

Stardust Memories is a short story compilation of human beings in the distant future where we have traveled deep into space. Each story describes a moral dilemma that people traveling in space may experience which is something that we have yet to determine in the current world.

Stardust Memories talk about such problems as the implications of having people travel for years, even decades, in the cold, quiet and endless universe. A different story tells on how human presence in a foreign galaxy will affect the environment. The topics the author decides to write about are interesting and makes you wonder about the future.

Sakichi sees his peaceful summer onstructed by a girl from the Edo period who assures that he's the reincarnation of his late lover.

Oneshot published under the label STUDIO MEN alongside with Majo wa Houki de Sora o Tobu .

A tale of obsessive love and constant pursuit, told over a 1000 years.
Escaping from a brother who had just ascended the throne, Yoshitsune, along with his servant, comes across a house in the middle of a desolate mountain. Oddly enough, only a young woman lives there, who seems to possess a very dark and ominous past.
This long journey of more than a thousand years focuses on our main protagonist Kurou. It can be somewhat confusing at the beginning, but once you understand the plot this story can be quite entertaining.
The main thrust of the story goes like this: Kurou meets a beautiful woman by the name of Kuromitsu, and begins a relationship which transcends life and memory. Kurozuka tells the tale of a journey undertaken by immortals, and those who chase after immortality.
The majority of this story takes place many centuries in the future, after Kurou has been separated from Kuromitsu. Having lost almost all of his memories, Kurou seeks to understand why he cannot die, to rediscover his identity, and to find the woman that haunts his dreams.

Nana, an apathetic 24-year-old with nothing much in her life, suffers a car accident and wakes up in her 14-year-old junior high body. As she lives through each day, she starts to remember things she buried deep in her memory, and she can now not remember being involved with her older sister, whom she deeply admires, and her sister's first love, a senior at her school.

The year is Universal Century 0096, and Banagher Links is a student at the Anaheim Electronics Industrial College training facility at an incomplete space colony. There, he rescues a girl named Audrey Burne and helps her to evade capture by Zeon remnants known as the Sleeves. The Sleeves are after "Laplace's Box" an item the Vist Foundation has had in its possession since the beginning of the Universal Century which can be used to topple the Earth Federation government, and Cardeas Vist, the head of the family plans to hand them the key to it. Audrey, fearful of what will happen, wants to convince Vist not to give them the key. The Earth Federation's Londo Bell unit attacks the Sleeves and Banagher is drawn into the chaos. Adapted from the light novel series that were later adapted into a feature film series, the first of which has already been released this February 2010.

27 years old, civil servant (government employee) examinee, Nam KiHan! One morning, when he woke up, he traveled back in time of 16 years! A scenario where everyone dreamt of at least once, reliving your life. Watch as Nam KiHan attemps to relive to become an elite of the society! Webtoon in Naver Please address this work as a Manhwa (Korean word for cartoons)

As a baby Jiro was delivered to his foster parents by a massive oni, who said he would return for Jiro in 15 years. When the time comes Jiro must contend with enemy oni, dark cultists, and their minions while attempting to protect both his parents and girlfriend from their depredations. Ultimately he must embark on a journey through the past, future, and other dimensions to embrace his destiny as Shuten Doji reborn.

One night an android which looked like a cat (a Necossass: Six type) suddenly appears in Katsuhiko Katsu's room. The android said that she comes from the 22nd century and that Katsu had left a note in a time capsule stating that he wanted to live with a robot-cat.

From MangaHelpers:

No one can make the perfect decision every time. Everyone has those moments that they wish they could redo and alter their decision. This story revolves around girls that got their second chance. [DrCoke]