Vermeil is a powerful and enigmatic demon who plays a central role in the series 'Kinsou no Vermeil'. Initially summoned by Alto Goldfield, Vermeil becomes his familiar, aiding him in his journey through the magical academy. Despite her fearsome strength, Vermeil often displays a playful and flirtatious demeanor, which contrasts with her fierce combat abilities. Her bond with Alto is complex, evolving from a simple contract to a deep mutual trust and understanding. Vermeil's presence introduces numerous challenges and opportunities, influencing Alto's growth as a magician and character.