This is Tomino's alternate version of "Char's Counterattack" which he proposed for the movie adaptation. He drew up a new story outline which added Beltorchika and turned Amuro into a family man. The sponsors didn't like the idea, and reverted to the original "High Streamer" storyline, but Tomino decided to write this new novel based on his rejected movie plot.

In U.C. 0093, Char Aznable returns as leader of Neo Zeon, and is determined to drop the asteroid base Axis on Earth. Opposing him is the task-force Londo Bell, led by Amuro Ray and his Gundam. The final battle will take place over the Earth Sphere.

(Source: Gundam Wikia)