KARD is one of the rare K-Pop groups that features both men and women (the industry, borrowing from educational terminology, refers to these groups as “co-ed”).
I can count the number of co-ed idol groups on one hand. The only other one that comes immediately to mind is the ill-fated Coed School; if you can think of any more, please yell at me in the comments. (I happen to like Coed School a lot, so stay tuned for a future post.)
This group is also notable for gaining an international fanbase through numerous overseas concerts and fan meetings before they really started to get popular domestically. They didn’t officially debut until 2017, but released a bunch of “project singles” starting in 2016, of which Oh NaNa is the first.