Ha Dong-kyun, officially known as Ha Dong Qn, is a South Korean singer-songwriter. He debuted in 2002 as a member of the short-lived boy band 7Dayz, before joining the boy band Wanted in 2004. As a solo singer, he has released two albums: Stand Alone (2006) and Another Corner (2008), and three extended plays: Mark (2012), Word (2014), and Polygon (2017).

Park Soo-young, known by the stage name Joy, is a South Korean singer, actress, and host. She debuted as a member of South Korean girl group Red Velvet in August 2014. In 2017, Joy debuted as an actress and has had starring roles in the television dramas The Liar and His Lover (2017), Tempted (2018), The One and Only (2021), and Once Upon a Small Town (2022). In 2021, Joy officially debuted as a soloist with the release of her special album Hello.