Many years ago, an ancient civilization ruled Earth. They had a very advanced technology, but were destroyed in the end due to the misuse of their creations. These people left messages for later generations in the form of indestructible message plates written in an ancient language.
Several armed organizations began to secretly search for these artifacts to use them for their own good and against their enemies. The ARCAM Corporation is trying to stop these forces from destroying themselves with these "advanced" machines. The main character of the story, Yu Ominae, is one of the elite agents that work for ARCAM under the name of Spriggans.

Murders done with unknown technology are perpertued in Japan. The Special Inverstigation Department of Science is set up to help the Police. Kyo Hoshina, a 12 year-old genius and Kyou Kugayama, a fighting game maniac, both in the special department, have to solve the case.

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...

14 year old Kimigawa Kento lives separated from his stepfather after his mothers death. A woman visits with a will sayings it's from his biological father. He refuses the will and she tells him the inheritance is approximately 1 trillion yen. He still doesn't what it and threatened with his friends family's jobs at the line he agrees to meet his relatives.

But all isn't as it seems. When he arrives at the house they are attacket. And he finds out the true meaning of the will...

From Yen Press:
Haruka Tooyama is a twelve-year-old girl with incredible precognitive abilities. But her accuracy in predicting the future has made her a target for any number of greedy corporations that would use her power for their own profit. When she is kidnapped, Haruka uses her gift to seek out someone who can help her escape and fixes upon a blind man making his way through the busy streets of Tokyo. Though it may seem an odd choice, Haruka's powers have not led her wrong. Despite his inability to see, her chosen protector’s fighting skills become apparent when he draws a sword from his walking stick and deftly takes out her captors. Knowing she will always be pursued for her gift, Haruka begs the mystery swordsman to keep her safe... "Until Death Do Us Part".