Note: her rank patch is that of a Master Sergeant, but if 小隊 is a platoon, seems she should be a Sergeant First Class? ja.wikipedia, though, lists a 小隊's commander as 1曹, which the crosswalk on its noncom page says is, indeed, Master Sergeant. I hope this isn't unusual...
Master Sergeant Olivia Christina Rockfield (age 18). Commander of the United States of Liberion Army's 24th Mechanized Infantry Division's 5th Witches Platoon, the "War Dogs". Her strikers are an M1A1 Abrams, and her standard armament consists of an M249 light machine gun and an M9 pistol. Her familiar is the Welsh Corgi. Born to a not particularly wealthy family in New York, she joined the Army at age 11. Gifted with magic that granted her superhuman strength, she's had experience rescuing survivors of natural disasters in Liberion from underneath rubble. She was deployed as part of the advance guard to the Mediterranean Sea in the Gulf Neuroi War and saw vicious action on the front lines. A devout Christian who will permit no blasphemy of her God and passionately fights against the Neuroi as messengers of the Devil. She's fairly well known even in the Air Force and the Marines for her unflinching courage in the face of death and her rough handling of her soldiers. "What are you trying to do to my team!? Just hit 'em with all you've got, everything! Over!"