WJSN member Dayoung appeared solo on KBS2's 'Immortal Songs' episode featuring Yoon Il-sang, showcasing various performances on stage.

After releasing her second digital single, "What's a girl to do," on the 7th, Dayoung has been actively promoting the song and participating in various broadcasts and content. In the waiting room talk, she introduced her new song and attracted attention by demonstrating a key choreography using a hooded zip-up. In response to the MCs' questions, she revealed her diet secret, saying, "I lost 1kg per month, totaling 12kg. It's good to gradually change eating habits."

On the broadcast, Dayoung chose Kim Gun-mo's "The Bird That Flew Over the Cuckoo's Nest" for her stage. She shared her thoughts on her family's support, saying, "This is a program my parents really like. Since my hometown is Jeju Island, they don't come to Seoul often, but this time they took a plane to come." She continued, "As soon as I saw the title 'The Bird That Flew Over the Cuckoo's Nest,' I decided to become the 'Cuckoo Girl.' I prepared cuckoo choreography and want everyone to remember, 'Who is that cuckoo girl?'"

On stage, she reversed the song's atmosphere with trendy rearranged rhythms, kitschy choreography, and a dance break using a hat, increasing audience engagement. Despite the intense choreography, her unwavering live vocals and refreshing high notes captivated the audience.

Im Han-byul, who watched Dayoung's performance, said, "After 10 years since debut, some might settle, but her constant challenges are admirable." Brave Girls' Minyoung and Mighty Mouth's Shorry responded with "So hot" and "So good I want to run away," respectively. Composer Yoon Il-sang commented, "'The Bird That Flew Over the Cuckoo's Nest'—if it had appeared at Coachella, this might have been the stage. It was really trendy. If I were to score it, it would be a perfect score."