In the year 123 of the Universal Century, skirmishes between the Federation government and the rebel group Crossbones Vanguard echo across Earth's space colonies. One of these small battles breaks in the hometown of young Seabook Arno, forcing him and his friends to flee and ensnaring them in the political turmoil that is quickly evolving into an all-out war. Seabook meets Cecily Fairchild, granddaughter of the aristocrat Meitzer Ronah, who seeks to create a new political power called "Cosmo Babylonia." Using the Crossbone Vanguard as its muscle, the Ronah family schemes to restore aristocratic rule and establish an economic system that will benefit the nobility, thus devastating the quality of life for the common people of the Earth Sphere. Seabook is tasked with piloting the Gundam F91, a mobile suit created by his mother, and must choose between protecting the status Federation's status quo or cooperating with Cecily to find a better way of life for all.

The anime will depict the lively everyday lives of the demon brothers through special episodes separate from the game’s main story (Lessons).

In the year Regild Century 1014, an entire millennium has passed since the end of the fabled Universal Century, where legends like Amuro Ray and Char Aznable ruled the battlefield as ace mobile suit pilots. The Earth's surface that was once hotly contested is now mostly abandoned, with humanity preferring to live in space colonies and the surface of the moon. Capital Guard Academy student Bellri Zenam lives a peaceful academic life, but his normal days are brought to an end with the capture of pirate pilot Aida Surugan and her mobile suit G-Self. Bellri feels a strong mental connection with the G-Self and discovers that he is able to pilot it. He soon finds himself in contention with the "Capital Guard," a radical faction that follows its own secret agenda despite the wishes of the Amerian Army, who still hold power on Earth. Joining the crew of the Amerian spaceship Megafauna, Bellri and Aida must pilot the G-Self to victory against the Capital Guard and its leaders, the charismatic Colonel Kunpa Rushita and the enigmatic Captain Mask.

When three complete strangers, Mishiba Toki, Nakajyo Nobuto, and Saitoh Kazuo, are hired by a corporation to compete in the Bus Game, an illegal dog-fight conducted in strict secrecy, they are given the team code of "Team AAA" (Triple Anonymous). This group of three who differ entirely from their living environments to their personalities have to work together effectively, but without mutually wiping out their mistrust of each other or prying into each other's privacy. They only have one point in common—each of them need a large amount of money for their individual circumstances. To get the money, they must play in the game despite their very own lives being at stake.