Two-Person Galactic Journey: Earth Was Destroyed While Imprisoned in Space Prison

Kait Crouch, who was banished from Earth as a thought criminal and incarcerated in a personal prison in outer space.

One day, just after finishing his daily routine training, he was informed of a grave fact by Emotion, his life support robot.

"The surface world has perished. With the demise of human society, I determine your sentence to be concluded."

Are there others similarly confined in personal prisons in outer space?
What about the state of things on the surface?
Survivors?

Casting aside all such ordinary questions, Kait says to Emotion with a smile.

"Alright, first things first, let's see how far we can go with the remaining food and oxygen."

This is a story of a single Earthling making contact with an extraterrestrial civilization and living freely in a new world.