Miia is a lamia, a liminal being with the upper body of a young woman and the lower body of a large red snake. She becomes the first monster girl placed into the care of Kimihito Kurusu as part of the Interspecies Cultural Exchange Program, originally intended for a different host family but brought to his home by a coordinator’s mistake. Impressed by Kimihito’s lack of prejudice and his kindness, she asks to remain with him and quickly develops deep romantic feelings for him, referring to him exclusively as darling. Her primary motivation throughout the story is to become his partner, and she pursues this goal with open enthusiasm, frequently attempting to seduce him and jealously guarding his attention from other liminal girls who later join the household. Her personality is energetic, passionate, and at times reckless, and she is characterized as a hopeless romantic who remains optimistic even when faced with strict interspecies regulations. She often acts domineering and hot-tempered, especially when she feels her claim on Kimihito is threatened, and she can be possessive and calculating in her efforts to secure his affection. Despite this abrasive side, she also has a softer nature: her love for Kimihito is sincere and protective, and she regularly puts herself in harm’s way when she fears his life is at risk. She also cares deeply for the other girls at the residence, even though she views them as rivals. In terms of development, she initially struggles with insecurity and fear of rejection from humans due to her hybrid nature, but over time she grows more confident, embraces her uniqueness, and becomes more proactive in protecting those she cares about. She evolves from a dependent character into someone who actively seeks to help and support her friends. Her notable abilities are rooted in her lamia physiology. She possesses a powerful, flexible tail that she uses for constriction, swimming, and climbing with enhanced agility and strength. She can move quickly and silently, though her effectiveness is reduced in environments that restrict her movement. As a poikilotherm, she struggles to move on cold days if her body temperature drops too low. She is notably bad at cooking and housework and has a distinct fear of amputations, becoming deeply disturbed when she sees severed body parts. Her relationships are central to her role. Kimihito Kurusu is the focal point of her affections and serves as both her protector and romantic interest. She interacts with other monster girls such as the harpy Papi, the centaur Centorea Shianus, and the arachne Rachnera Arachnera, each relationship reflecting a mix of rivalry, friendship, and empathy. The coordinator Kuroko Smith provides guidance and occasional conflict as she oversees the household. Miia’s position as the first liminal to live with Kimihito establishes her as the primary heroine and sets the tone for the series’ exploration of interspecies coexistence and romance.