Ginga Tansa 2100-nen: Border Planet

Subaru, Prokion, and Mira grow up as inseparable childhood friends, but adulthood changes their bond when Mira marries Prokion. Subaru accepts the pain quietly, determined to remain loyal to both. Then Prokion contracts a terrifying extraterrestrial virus brought through a spaceport and dies after returning home, leaving Mira exposed to the same infection.

The only way to stop the pathogen is to keep Mira frozen below zero. Refusing to let her remain suspended forever, Subaru leaves Earth to trace the virus to its source and find a cure. His search carries him across strange planets and abandoned corners of space, where each new world reveals another danger waiting at the edge of humanity's expansion.