A manga adaptation of the first Medarot game. Created by Horuma Rin, the artist for the game series.

The story follows Hikaru Agata and his medarot, Metabee's adventures.

Fifteen years ago, natality decreased greatly in Japan and the few who were born during that time are called the "Old Generation" or "Oldgens."
Hanasaka Haru, a 15-year-old Oldgen, has never met any classmates before. Now, he goes to school for the first time and meets Himeshiro Sakurako. But Sakurako is not quite the ideal classmate he imagined, and his dream school life isn't turning out the way he wanted it to...

A group of high-school students had an accident on their way to a trip and died but they find themselves in a classroom with a black sphere.

In 2016 a meltdown of a nuclear power plant creates a big catastrophe in Tokyo. 20 years later, the city has become a ghost town due to the high levels of radiation. From that area a distress signal is received, the Self-Defense Forces dispatch three girls from the special unit Coppelion to search for survivors. But why aren't they wearing any protection against radiation?

On the planet Paradyze, a war between the surface and underworld has been going on for centuries. A young cyborg fox named Maze fights for the resistance against the underworld, but has lost hope for an end to the war...until an alien named Grumble crash lands on his planet, and brings with him the technology to change everything...

Plot revolves around high school freshman Shingo Susa as he is invited by his crush from middle school Sayuri Shiroyuki to the school's supernatural club. Over the course of the series Susa begins to gain supernatural powers, something that prodigy Rei Uryu, attempts to awaken to bring out the psychic giant, Susano Oh to destroy humanity and establish a new world order.

Won the 4th Kodansha Manga Award for Shounen in 1980.

From Aerandria Scans:

Noriko is caught up in an accident while she is going to her track and field competition. When she opens her eyes, there is the young doctor Shinoda who seems very concerned about her. She is attracted to his child-like smile, but from his lips, she learns a shocking truth - in the accident, Noriko has lost her physical body and what remains is only a brain, stuck in a little black box?!

Note: The side stories in volume 1, 2 & 3 are written in novel format.

The Freezing Pair Love Stories manga tells the story of how the various Pandoras and Limiters met. The first chapter focuses on the characters Ganessa Roland and Arthur Crypton.

From MangaHelpers:
Yasaka Tokiwa lives in an unusual time, and according to his dreams, it's about to become even stranger. He's been having a dream of a woman called Ri'in ever since the robot, who he calls Makina, came to his home. He and Makina attend the same school, where their other classmates include a secret ninja (Kusanagi Kanata) and a sorcerer (Yata Haruka).
When Tokiwa, the robot, the ninja, and the sorcerer rush to rescue the student council president from a demon, the boys find that they've all been having the same dream! What is going to happen to their world?

Inuyashiki has a family, a wife and two kids, none of which care about him. When he learns that he has only three months to live he realizes that the only one who will miss him is his dog. Shortly after this realization he is killed in a crash landing by aliens. He is rebuilt by them as a machine with a human exterior. How will his life change now that he isn't human.

From MangaHelpers:

Shou lives out in the country. He has a big crush on his childhood friend Sora, but is afraid that she thinks of him only as a little brother. One day, Sora announces that she was abducted by aliens. Later that day, Shou confesses his feelings for her and she dies shortly afterward. Shou is still in shock from her loss, when an alien girl named Lila comes down from the sky. She has a disk that contains a brain scan of Sora, and she can run Sora's personality in her own body. She also wants to have a child with him. Will Shou be able to cope with all of these sudden changes, and will he be able to keep Sora with him after all?

Plants have taken over the planet.
In 2017, the vegetation in Tokyo rose up and toppled human society in moments.
The few survivors are forced to live in the relative safety of a subway network, but supplies are running low.
Join an average high school student named Akira as he challenges the plants in a struggle for survival!

A story about a girl being kept in isolation in a world that appears to have experienced an earthquake and nuclear disaster.

"Three years ago, he had the same posture.
Three years ago, he had stood behind Miyuki.
Yes.... Compared to three years ago, it had changed."

Set three years prior to the present time, Tsuioku Hen tells the events that would change Miyuki's world drastically, as well as the events that led Tatsuya to become what he is now.

(Adaption of Light Novel v08)

A girl who belongs in a different time. A boy possessed by an emptiness as deep as space. A story about an alien artifact, a mysterious murder, and a love that crosses light years.

From Easy Going Scans:

In the near future, Mother Nature has decided to fight back against all human encroachment.

The world has entered your standard apocalyptic scenario that you can find in many forms of fiction, but it's right in the middle of the apocalypse actually happening, rather than in the aftermath. Vines and foliage entangle cities, as large wooden mech-like creatures called Arethusa (named after one of the mythical Greek Hesperides that tended the gardens in a remote corner of the world) rampage through cities.

Souma Shin, a punk kid out of Japan, went to visit his brother Ken, but all hell breaks loose as Shin finds a group of small kids being used for military purposes. He tries to save them in the confusion created by an Arethusa invading the compound...

From Yen Press:
Yuki Nagato, the shy president of the literature club, has never been very sure of herself around other people. But around Kyon, the only boy in the tiny, three-person club, Yuki finds herself faltering even more than usual. For Kyon, and for her precious club, Yuki must find her confidence and let her true personality shine! Enjoy taking a fresh look at your favorite characters in this brand-new story set in the world of The Disappearance of Haruhi Suzumiya.

From asdf scans:
In near future, mankind has been defeated by the viral parasites named "Gastrea." They have been exiled into a small territory and live in despair, side by side with terror. In this world trapped in darkness Rentaro, a boy living near Tokyo and a member of the "Civil Security"—an organization specializing in fighting against the Gastrea—is used to accomplishing dangerous tasks. His partner is Enju, a precocious young girl. They fight using their peculiar powers until one day, they receive a special assignment from the government. This top secret mission is to prevent the destruction of Tokyo. Set in a near future, this thrilling heroic-action story starts now.

This is a spin off story that occurs about three years before Spiral. One of the main characters is Imari, who is in love with the kid who wants to be a detective, and which also quit school running after Kiyotaka, and it seems he's dating a murderer without knowing it...? But how is it all connected to the blade children? Not long after, our favorite blade children from Spiral appear for the rescue, all manipulated by Kiyotaka.

Lunarbaboon is a half man/half moon monkey trying to make sense of it all.