A kid inherits a mobile suit that shouldn't exist, and the entire UC timeline bends itself trying to keep him from opening a box that rewrites what the war was actually about. The Unicorn's transformation sequences are the most visually deliberate things Gundam has ever done, each one a statement that something impossible is becoming real. This is UC Gundam asking itself what happens when the ghosts of a hundred-year conflict get a second chance to change their own ending.

In Universal Century 0096, three years after Char Aznable's failed bid to push humanity into space, sixteen-year-old Banagher Links lives a quiet student life on Industrial 7, an unfinished colony at Side 4. He has grown up never knowing his father. His routine changes when he meets Audrey Burne, the last heir of a tyrannical family, who has secretly boarded a ship to the colony. She is seeking the key to Laplace's Box, a device said to be able to decide the future of the universe, and she hopes to keep it away from the Sleeves, the last remnant of Char's Neo-Zeon. When the Sleeves strike Side 4, with their skilled pilots Marida Cruz and Full Frontal among the attackers, Banagher takes the controls of the newly built white Unicorn Gundam to protect his friends. Based on Fukui Harutoshi's novels, this seven-episode OVA mixes mecha action and science fiction drama.