Girl's Day Hyeri shared photos of herself and Rosé hanging out together on February 18.
She added the caption, "One week ago," to explain that the photos were taken on Rosé's birthday on February 11.
In the photos, the two idols smile in front of the balloons, outlining their initials "CY" for Rosé's real name, Chae Young, and "HR" for Hyeri with a heart in between, as well as "Happy Birthday".
Rosé and Hyeri are best friends who recently spoke on an episode of tvN's "Amazing Saturday" about their relationship. They also showed support for each other's ventures and recorded on Hyeri's vlog one of their hangouts.