The Master is the owner of the coffee shop Angel Coffee, where the fallen angel Gabriel White Tenma works part-time. He also owns the apartment complex in which the demon Satanichia Kurumizawa McDowell lives, making him her landlord. He is an adult human man with a gentle and extremely mild-mannered personality. His primary passion is coffee, and he takes coffee-making very seriously, often displaying an almost obsessive dedication to the craft. Despite his earnest demeanor, he is frequently bewildered by Gabriel's lazy and erratic behavior. Because Gabriel is from Heaven and unfamiliar with Earth customs, he mistakenly believes she is a foreigner struggling with a language barrier, and he regularly misinterprets her rude or unorthodox customer service as endearing quirks, praising her for them. His motivations are simply to run his coffee shop smoothly and to be a good employer and landlord. He is kind-hearted and caring at heart, though his interactions with the main cast are limited to workplace and rental situations. Within the story, he serves as a supporting slice-of-life character who grounds the supernatural antics in a normal human setting. He has no notable supernatural abilities, but his expertise in coffee-making is a defining trait. The Master does not undergo significant character development; his role remains consistent as a benign, slightly confused authority figure who accepts Gabriel's strangeness with patience.