A new era begins in a devastated world gripped by nuclear winter. Humans are no longer in control of the world, and crises emerged one after another. As mankind tried to rebuild order, the protagonist Ren Xiaosu stepped up with his positive energy, and in the process changed the world.

In the near future, technology has made a few leaps and bounds, and videophones and constant wireless internet access are available to everyone. However, it would seen that the government has been careless and a skilled hacker was able to break into the national information archive. Using the data held there he creates the Platonic Chain website for people to discover information about themselves and their friends. Words start to spread quickly that there is a site that enables you to look up anything. Coincidentally, three young girls, Hitomi, Rika, and Kanae, are able to access the site. This is a 15 minutes special to the TV series, Platonic Chain.

The artificial sun that lights the frozen planet La Metalle is dying, threatening to extinguish what little life is left there. Queen La Andromeda Prometheum decides that the only way for her people to survive is for them to submit to Hardgear's transformation process, which will turn everyone's body into machines. The Queen's daughters, Emeraldas and Maetel, refuse to submit to this process, and fight to stay human.

Having failed the Comet Blaster exams mysteriously, Mikaze and her friends are sent back to the Shimoji Island base, where, with three new Meteor Sweeper trainees around, they have been promoted to instructor positions. Meanwhile, more comets are on their way to Earth, and the mysteries behind the rift in the Cosmic Emergency Management Agency—as well as the alien parasites—begins to unravel.