The Third Prince first heard of the Prison Planet when he was twelve years old.
Books brought by foreign merchants would often appear in the library, which was also his main way to learn about the universe. Most civilizations were similar to the Blue Star, but in the depths of this vast cosmos, there were some abnormal planets.
One kind turned into Dead Stars after undergoing "Cocoon" transformation; another kind were planets like the Prison Planet, which were later modified.
Most of these planets were used for heavy industry production by companies and Chambers of Commerce, but the Prison Planet was unique. The company transformed the entire planet into the most secure prison in the universe, for detaining infamous criminals whose names would go down in history books.
According to recent statements from the Chamber of Commerce, they believed that Duan Mingyuan also should be sent to the Prison Planet for trial.