Today, actress So Yi Hyun wrote on her Twitter page, “Thirty years old birthday party. With ‘Who Are You.’ Feeling good! To my lovely staff and you too, Gun Woo! Thank you,” and posted a collection of photos from the party. In the pictures, the actress is wearing a birthday hat with a cake in front of her. She seems especially happy in a photo with Taecyeon handing her a gift. We wish we were invited!