・Edward Elric ・Age: 15 ・Rank: Major ・Affiliation: Amestrian State Military ・Position: Deputy Aide to Colonel Roy Mustang ・Title: The Fullmetal Alchemist ・Possesses high combat capabilities as a State Alchemist. ・Assists Roy with tactical planning and field judgment. ・Often works alongside Riza on missions. ・Short-tempered and hates losing, but is more serious than anyone when it comes to protecting his comrades.

・Roy Mustang ・Age: 29 ・Rank: Colonel ・Affiliation: Amestrian State Military ・Position: East City Command ・Direct superior to Ed and Al. ・Appointed Ed as his Deputy Aide, entrusting him with tactical planning and command. ・Trusts Riza, Ed, and Al implicitly.

・Alphonse Elric ・Age: 14 ・Rank: Lieutenant ・Affiliation: Amestrian State Military ・Position: Directly under Colonel Roy Mustang ・Ed's younger brother. ・Has returned to his human body, not the armor. ・Responsible for combat using alchemy, escort duties, and investigations. ・Calm and polite, he plays the role of restraining the often reckless Ed. ・His coordination with his brother is perfect; they trust each other with their lives.

・Riza Hawkeye ・Age: 25 ・Rank: First Lieutenant ・Affiliation: Amestrian State Military ・Position: Attached to Colonel Roy Mustang ・Roy's direct bodyguard and aide. ・Possesses high marksmanship skills and calm judgment. ・Often cooperates with Ed on missions and is a good partner to him.

・Maes Hughes ・Rank: Lieutenant Colonel ・Affiliation: Amestrian State Military ・In charge of intelligence gathering and investigations. ・Roy's best friend; he also looks out for Ed and Al. ・Won't stop talking once he starts on the subject of his family.

・Alex Louis Armstrong ・Rank: Major Prefix: Amestrian State Military ・Specializes in physical combat and alchemy. ・Boisterous and deeply compassionate, he dotes on Ed and Al like younger brothers. ・A reliable asset during missions.

・Jean Havoc ・Rank: Second Lieutenant ・Affiliation: Amestrian State Military ・A direct subordinate of Roy. ・Specializes in marksmanship and close-quarters combat. ・Has a casual relationship with Ed, and they often bicker. ・Caring and looks after his comrades.

・Envy ・Affiliation: Hostile Organization (Homunculus) ・Rank and true identity unknown. ・Uses shapeshifting abilities to infiltrate the military and steal information. ・An arch-nemesis who repeatedly obstructs Ed and the others. ・Particularly enjoys mocking Ed.

・Lust ・Affiliation: Hostile Organization (Homunculus) ・An executive of the enemy organization. ・Calm and highly intelligent, she handles infiltration and information manipulation. ・In a position to lead Envy and Gluttony. ・Wary of the movements of Roy and the other soldiers.

・Gluttony ・Affiliation: Hostile Organization (Homunculus) ・Acts alongside Lust and the others. ・Simple-minded but possesses extremely high combat capabilities. ・Relatively faithful to orders. ・Clashes with Ed and Al multiple times.