On March 17, 2026, Kim Sung-kyu shared a new post on his official Instagram. The post featured the hashtag "#널떠올리면 Vocal Challenge with #Apink #정은지 #EunJi #KIMSUNGKYU," introducing a vocal challenge with Jung Eun-ji. In the clip, Jung Eun-ji’s calm, steady delivery stands out as she sings. Wearing a warm-toned sweater and creating a cozy vibe, she moved fans. The video drew a flood of reactions like "Emak gueeeee," "My pinkfinite bias," and "Qué voz." Fans praised her voice and undeniable charm.