Otoha Kisaragi serves as the head maid at the Himemiya estate, demonstrating unwavering loyalty and devotion to Chikane Himemiya as her primary attendant. Her appearance features shoulder-length blond wavy hair styled in ringlets at the ends, with bangs swept to the left, and brown eyes. She wears a distinctive maid uniform consisting of a dark cinnamon dress, white apron, white cap, hazel stockings, and hazel patent Mary Jane shoes.

Her personality centers on deep dedication to Chikane, which manifests as intense jealousy when Himeko Kurusugawa arrives to live at the estate. Otoha perceives Himeko as disrupting her bond with Chikane and resents her for causing her mistress pain. This resentment leads her to notice and exploit Himeko's dislike of mushrooms, deliberately serving them as subtle retaliation.

Early in the series, Otoha assists Chikane in selecting a dress for her birthday party, noting the unusual indecision compared to Chikane's typical decisiveness. After Himeko's arrival, Otoha becomes the first to recognize the romantic attraction between Chikane and Himeko, fueling her hostility. Her role includes both humorous moments and significant dramatic scenes, particularly highlighting Chikane's exclusive emotional focus on Himeko.

A pivotal development occurs when Otoha is sent to Tokyo to care for Chikane's ill uncle. During their farewell, she tearfully confesses her profound care and admiration for Chikane. This emotional exchange culminates in Chikane embracing and thanking her, causing Otoha to blush and cry. Later, Otoha writes a letter to Himeko, emphasizing Chikane's need for her support, signaling a shift from resentment to reluctant acceptance of their bond.

The etymology of her name reflects aspects of her character: "Otoha" combines "witty," "spicy," or "chic" (乙) with "feather" (羽), while "Kisaragi" means "February" (如月).