f(x) and CSJH's Dana & Sunday revealed their close relationship by uploading pictures of the two groups posing together. While f(x) were in their bold red stage costumes, CSJH showed off their chic femininity in matching black outfits. The two groups look like they are actually one because they all look so friendly and comfortable with one another, even posing as one group in the above picture. On the day these pictures were taken, f(x) said good-bye with performances of "Pinocchio" and "Hot Summer", while CSJH made their comeback as a two-member unit with "One More Chance". f(x) has passed the baton and will hopefully get to rest while CSJH promotes their electronic dance song, which has an addictive melody with a beat that is both strong and elegant. Check out the two groups below as they first pose seriously then lighten up with cute expressions! In addition, the girls also posed with SHINee's Key, Minho and Taemin who was also at Inkigayo for a special stage with f(x) last Sunday. [gallery] Source & Photos: Newsen via Nate