HMX-17c Silfa is the third unit in the HMX-17 series of humanoid robot maids, following her designated sisters Ilfa (HMX-17a) and Milfa (HMX-17b). Assigned as a personal maid to Takaaki Kouno, she demonstrates notably poor performance in household duties and domestic tasks. Silfa exhibits extreme emotional volatility and severe shyness, unusual for a robot. Her personality includes crippling social anxiety, often described as "hikkikomori" due to her fear of interacting outside her immediate circle. This anxiety manifests in a tendency to hide under a cardboard box for comfort and security. She typically refers to herself in the third person and speaks with a lisp. Her emotional instability sometimes requires disciplinary intervention from Ilfa. Across media like OVAs and spin-offs, her core traits remain consistent while showing situational development. In beach-themed episodes and spin-offs such as *To Heart 2: Dungeon Travelers*, she appears in summer attire like a pink bikini, though her timid behavior persists. The *AnotherDays* OVAs feature her in comedic scenarios, including an amnesia incident where characters attempt to manipulate Takaaki's memories, reflecting her ongoing integration attempts despite anxieties. Later *ad Plus* narratives identify her as exhibiting tsundere tendencies. Physically, Silfa has blonde hair styled in a long braid with blunt bangs, teal eyes, and a slim figure measuring 153 cm tall with bust-waist-hip measurements of 82-56-82 cm. Her standard attire is a maid uniform with ribbons, a miniskirt, puffy sleeves, thigh-high stockings, and Mary Jane shoes. Alternative outfits, such as the pink bikini in summer settings, appear in non-canonical merchandise and spin-offs. Her relationships center on her sisters: Ilfa acts as an authority figure enforcing discipline, while Milfa shares the HMX-17 series designation. She resides with the Himeyuri twins, Sango and Ruri, though their familial connection is not elaborated upon. Sango, a technician involved in gynoid development, is indirectly linked through Kurusugawa Electronics' robotics projects. No significant character evolution or resolution of her social anxiety is documented across official media. Her role primarily provides comic relief through her phobias and interactions, maintaining her defining traits of shyness and emotional fragility throughout all appearances.