Henry Henderson teaches History and serves as housemaster of Dormitory 3, Cecile Hall, at Eden Academy. He presents a distinguished appearance: long, straight white hair pulled into a tight ponytail extending below his shoulders, paired with a prominent Imperial-style beard featuring two pointed ends reaching his collarbone. Noticeable wrinkles frame his thin eyes and brows, and he consistently wears a monocle over his left eye. His attire typically consists of a dark three-piece suit with coattails, striped pants, a pocket square, a tricolor-striped tie, and he carries a cane. He places paramount importance on "elegance," considering it fundamental to personal conduct and societal betterment. This principle dictates his interactions; he corrects inelegant behavior while acknowledging children's occasional need to frolic. Though usually composed, he may lose composure when shocked or excited. Discipline manifests in his daily exercise routines, and he maintains firm authority supervising students and staff. During the Forger family's Eden admissions interview, he remained calm amidst disruptions but later punched Murdoch Swan for threatening behavior, demonstrating his readiness to defend his values through action. His backstory reveals attendance at Eden Academy in his youth. There, he first encountered Martha Marriott during a ballet performance, an event that inspired his iconic "elegant" exclamation, later becoming his catchphrase. Strict adherence to etiquette and rules, guided by his father's advice to "be ever a gentleman," resulted in social isolation and bullying. Martha intervened during one such incident, fostering a bond. Despite developing feelings for her, Henderson declined her invitation to a graduation dance, prioritizing his ambition to combat societal corruption through education. After graduating, he returned to Eden as a History teacher. As war tensions escalated between Ostania and Westalis, his idealism about education's power to prevent conflict clashed with Martha's decision to join the war effort. Believing she died in combat, he grew embittered and publicly denounced the war, leading to his arrest. His father intervened, urging him to refocus on teaching. This experience reshaped his perspective; he dedicated himself to nurturing students toward a peaceful future, influenced by Martha's past letters describing her hopes for the youth. In the present timeline, Henderson reconnects with Martha, now Becky Blackbell's caretaker. He invites her to a school dance, reflecting unresolved feelings from their youth, highlighting themes of regret and reconciliation with implications for his ongoing character development. Beyond History instruction, he oversees Cecile Hall's operations, disciplines students, and substitutes for absent teachers in subjects like gym and art. He maintains physical fitness through morning jogs and exhibits unexpected strength, as demonstrated when punching Swan. He corresponds regularly with a daughter and son-in-law, prefers scones during tea, and owns a chair designed by Frank Lloyd Wright.