JACK, a CIA operative, serves as supervisor for Manami Kinjou. Despite the masculine codename, she is female, bearing the full name Janis Alectos Carotenas Karinato.

Her characterization highlights stereotypical American traits through attire: a cowboy hat, denim shorts, belt, cowboy boots, and tank top. She frequently consumes fast food, reflecting a cultural trope. Her personal vehicle is a 1963 Chevrolet Corvette Stingray.

Within the narrative, JACK operates professionally to oversee Manami's activities in the CIA recruitment program.