Heinojō Nagatsuki is the personal butler of Aoi Kannazuki, serving her with unwavering dedication. He consistently wears a distinctive eye patch over one eye and demonstrates notable combat abilities indicative of a warrior's background. A recurring trait is his tendency to appear suddenly and unexpectedly to assist or attend to Aoi. The information provides no further details regarding his background, personal history, relationships outside his service to Aoi, or character development in other media.