Henry Williams is the second son of the noble Williams family and the twin brother of Alan Williams. He is also three years older than his sister, the main character Alicia Williams. In the context of the otome game that serves as the basis for the story's world, Henry is a character who can be romanced. In the anime adaptation, his Japanese voice actor is Haruki Ishiya.

Henry is characterized by a thoughtful and calm personality, setting him apart within his own family. While many of his relatives, including his brothers Albert and Alan, are quickly drawn to the heroine Liz Cather, Henry maintains a level-headed disposition. He does not follow others blindly and values fairness and logical thinking. This trait is most evident when he listens to Alicia's reasonable arguments and decides they make more sense than simply following the crowd. He is shown to be a caring and supportive brother to Alicia, genuinely wishing to stand by her side. Furthermore, Henry is notably open-minded and respectful toward those of lower social standing; when a commoner named Gill becomes Alicia's follower, Henry does not look down on him but instead welcomes him kindly, which is an unusual attitude among the nobility.

Initially, Henry finds himself influenced by Liz Cather's charisma and begins to align with her group, following the same path as his brothers. However, a major turning point occurs when Alicia confronts Liz Cather and presents her own logical and courageous opinions. Recognizing the validity of Alicia's views, Henry decides to change his allegiance and support his sister instead. This decision distances him from his twin brother Alan, who remains loyal to Liz Cather, and from Albert, who becomes hostile toward Alicia for rejecting the popular heroine. Consequently, Henry becomes a rare and crucial ally for Alicia as the Williams family becomes deeply divided. He feels sadness over this family conflict, particularly distressed by the cruel and unfair behavior his brothers display toward Alicia and Gill. At one point, after Alicia and Gill are attacked at the academy, Henry helps take care of Gill while witnessing his brothers' shameful support of Liz Cather, who blames Alicia for the incident.

As a character, Henry does not possess flashy magical or combative abilities often highlighted in the narrative. Instead, his notable abilities lie in his judgment and moral strength. His primary role in the story is to provide crucial familial support to the protagonist, acting as a voice of reason and fairness. His development is marked by his journey from being passively swept up by the heroine's influence to actively thinking for himself and choosing a side based on logic and his own sense of justice, even if it means going against the majority of his powerful family.