Henry Henderson/Relationships

Anya Forger
Henry initially had a poor impression of Anya before meeting her as he was unimpressed with her score on the admissions test. When they meet at the family interview, he is impressed by Anya's statement that she wishes to learn more about the school's headmaster, which is furthered when he hears what her resolve is, though he is unaware that Anya was referring to her spy show. After the Forgers leave the interview due to Murdoch Swan's malicious remarks, Henry punches the man in defense of them and ensures that Anya is placed at the top of the waiting list, knowing they are worthy of holding a place at Eden.

As a result of punching Murdoch, Henderson is demoted to teaching the first-year students of his hall, which Anya happens to be a part of. On orientation day, he intervenes when Anya punches Damian. While Henry sees it elegant after hearing Anya explain that she punched Damian in defense of Becky, he still gives her a Tonitrus Bolt for her actions but is able to reduce it from being three.

As Anya's teacher, Henry is often disappointed by her poor grades and even has her attend remedial classes before the midterms. When he warns his class about getting Tonitrus Bolts, he frequently looks at Anya specifically, though she does not understand why. When Anya gets her first Stella Star for saving the life of a drowning boy, Henry is impressed and proud of his student's achievement.

After Anya gets her second Tonitrus from Donna Schlag for not having her handkerchief, Henry shows his concern by asking how she is faring. After he fails to explain to Anya the importance of one's attitude towards preparation and self-control, the topic changes to Imperial Scholarship and Henry gets upset when Anya makes light of getting it and Stella Stars. He proceeds to walk her through Eden Academy's Hall of Fame to stress the efforts of those who became Imperial Scholars, teaching her to be patient in reaching her goals.

Anya continues to manage shocking Henry from either impression or bewilderment. After he teaches her to be patient in her goals, he attempts to help her study with questions she got wrong on a quiz, but she quickly leaves to watch her cartoon, stunning him. During the hijacking crisis with the Red Circus, Henry enters the bus to put his students' minds at ease, and is upset to see that Anya also has the neck bomb he heard about. However, Henry is shocked by Anya's casual behavior, and when she boldly confronts and throws a tantrum at their captors, Henry is amazed by her "nerves of steel" and "tungsten." After the crisis passes, he is relieved to see that Anya is still a child after watching her run to Yor while in tears.

Damian Desmond
As Damian's teacher, Henry treats him with the same strictness and sincerity he gives to his other students. After witnessing Damian and Anya's initially rocky relationship at the start of school, Henry sees the rare moments of them cooperating with each other as interesting developments. When Henry admonishes Damian for his rude behavior toward Anya during art class, he notices the boy swelling up with tears and instructs him not to rush and to do the best he can do right now. After Damian's art project ends up winning the art contest, Henry is quite bewildered by the result.

After the Imperial Scholars mixer, Henry punishes Damian for missing morning muster by assigning him to help the dorm mother with chores. He later sees his friends, Ewen and Emile, purposefully misbehave around the dorm and punishes them with the same task. As he watches the boys fool around and play during chores, Henry thinks how elegant their youthful friendship is. After seeing Damian look to the sky in a daze and hearing Mr. Green's comment that he looks like he would rather be at a picnic, Henry decides to help Damian and his friends "let loose" by having them go on a field research trip with Mr. Green.

Murdoch Swan
Henry and Murdoch Swan do not have a good relationship. During the interview with the Forger family in the admissions exams, Henry disliked Murdoch's impolite questions and comments. After the interview escalated into Loid smashing the table after Murdoch further insulted the family, the Forgers left the interview, and Henry called Murdoch out for going too far. Murdoch responded by threatening Henry with his father's influence, but after remembering Loid's praise for their school's educators, Henry refused to stand by and punched Murdoch in the face for disgracing Eden Academy, knocking the man out cold.

After this incident, Henry is not fired from Eden but instead put in charge of the first-year students of the new term, much to Murdoch's annoyance.

Donna Schlag
As fellow teachers at Eden Academy, Henry and Donna are familiar with each other. When she returns to Eden after her hospitalization, Henry sees that she is already back in form of punishing students but wonders if she is over-doing it. Donna is surprised and believes that he has gotten soft due to the influence of his first-year students. While her methods are strict, Henderson hopes they are her way of refocusing the student body as they acclimate to school life.

Loid Forger
Henderson has a deep respect for Loid, having personally acknowledged the man's "elegance" and being deeply impressed by his ideals. Loid's actions at the admissions interview caused Henderson to completely reevaluate his approach to being an educator and reminded him of his own convictions, which caused him to punch the cruel Murdoch Swan. Henry holds Loid in high regard, and is shocked when he hears about his activities in Anya's report on his job, though Loid quickly gets out of trouble after explaining himself.

Martha Marriott
Henry and Martha appear to share a history, shown when they immediately recognize each other during the Red Circus hijacking crisis. When Henry offers himself to the terrorists in exchange for getting the dorm tutor to a hospital, Martha calls him a fool and worries about his situation.