U.C. 0097, one year after the opening of "Laplace's Box".

Despite the revelation of the Universal Century Charter that acknowledges the existence and rights of Newtypes, the framework of the world has not been greatly altered.

The conflict later dubbed the "Laplace Incident" is thought to have ended with the downfall of the Neo Zeon remnants known as the Sleeves. In its final battle, two full psycho-frame mobile suits displayed power beyond human understanding. The white unicorn and the black lion were sealed away to remove this danger from people's consciousness, and they should now be completely forgotten.

However, the RX-0 Unicorn Gundam 03, which disappeared two years earlier, is now about to show itself in the Earth Sphere once more. A golden phoenix… named Phenex.

From Storm in Heaven:

Matsumiya Kana lost everything when her father was arrested and charged with embezzling funds from the Japanese Ministry of Defense. However, she soon learns that her father actually worked for a secret organization within the Department of Internal Affairs, and was in charge of embezzling money to support it off the books. He was being used by an "embezzlement group" within the secret organization, and that group is willing to kill to keep their activities quiet. The life of his daughter, Kana, is the perfect blackmail to ensure his silence. Within a corrupt agency, where anyone could be a traitor, will Kana be able to avoid falling into the hands of those plotting against her...?