I'm not entirely sure if they're really sisters or just good friends but there's two women that make up the artist team. I dont think they've ever made any public appearances, but the older of the two does most of the social media stuff. I dont know how they break up the work for the stories though.
I VPNed to Seoul and read some Korean blogs. It seems that was just a rumor that was floating around a few years ago and has since been debunked. Artis is just able to churn work out really fast and has a good assistant team, so people thought it was more than one person, but I dont think anyone really knows for sure...
(/TДT)/