Keiko participated in the Fuso Sea Incident as the Fuso Army Witch. She scored top kills at 6 consecutive kills. However, the Army used Anabuki Tomoko for its propaganda movie because Keiko's fighting style was not dogfight-based. Because of that, Keiko attempted a difficult and dangerous maneuver at the victory parade and crashed, sustaining severe injuries. Due to her injuries and the fact that she turned 20 while recuperating, she retired after giving up on returning to active duty, becoming a war correspondent. However, her reinstatement application resulted in her being assigned to the post of commanding officer for the Fuso Imperial Army African Expeditionary Force Independent Flight Squadron with the rank of Flight Lieutenant.