Sergei Cherenkov is a fellow Mobile Infantry soldier fighting alongside Johnny Rico against an alien species in an interstellar war. He fights on the mission to the enemy base planet Kurendatsu. During intense combat against hostile alien forces on Kurendatsu, Cherenkov is killed in action. His death deeply impacts Rico, contributing to Rico's understanding of warfare's brutal realities and the value of life—including that of the alien adversaries. This event reinforces Rico's evolving perspective that soldiers fight fundamentally to survive. The narrative significance of Cherenkov's character is underscored by the OVA dedicating an entire episode, titled "Cherenkov," to him. His character appears solely in this single OVA adaptation.