Rookie group AOA's Yuna recently celebrated the big 2-1, marking an important day for the girl group member.

"Hello this is Yuna?" she posted on her Twitter, along with a photo of her holding a celebratory birthday cake in the shape of a heart and emblazoned with her name. "Today is my 21st birthday!! Thank you so much to everyone who congratulated me, I shared this pretty cake with our members? I'm so happy on this very special day."

Happy birthday, Yuna!