Fenneko's appearance is based on a Fennec Fox. She has light fawn fur across her entire body except for a dark fawn tripoint stripe down her forehead. She has a noticeably short height.

Like Retsuko, Fenneko wears a navy blue vest and skirt, a white dress shirt, and brown heels at work. Outside of work, Fenneko is seen wearing a baby blue turtleneck sweater, gray skirt, black tights, and brown boots. Fenneko is Retsuko's closest co-worker and is a renowned social media stalker. She is good friends with Retsuko and Haida