Maria van Hossen, the spirited younger sister of Sylvia van Hossen, radiates a bubbly, cheerful demeanor. She shares an intensely close bond with her father, Vincent van Hossen, often clinging to him with playful devotion. Shaped by Vincent’s emphasis on egalitarian ideals, she forges relationships through genuine connection, valuing shared interests over societal rank or aesthetics. Her instant camaraderie with Teppei Arima—playfully dubbing him “Onii-chan” after his engagement to Sylvia—highlights her eager embrace of him as family. This affectionate nickname mirrors her unwavering support for their union. Maria idolizes Sylvia, seeing her as not only an aspirational figure but also a poignant reminder of their late mother, whose features Sylvia inherits. Whether engaging Teppei, the Arima housemaid Yū Fujikura, or others, Maria navigates social interactions with disarming warmth and effortless charm, reflecting her naturally gregarious spirit. Across her documented appearances, she remains a linchpin of familial harmony, embodying the role of the devoted younger sibling who nurtures bonds with unwavering optimism.