At first, Sunmi called her dongsaeng Seulgi before Red Velvet's concert began, "informing" her that she couldn't attend due to other schedules. Feigning her absence, Sunmi sent over her encouragements for the concert over the phone, also greeting Seulgi's fellow member/Han Chae Young's dongsaeng Yeri for the first time.†
However, Sunmi and Han Chae Young both attended the concert as originally planned, enjoying the show from the audience until the end. Afterward, the two unnies sat waiting in a waiting room as the 'Secret Unnie' staff led Seulgi and Yeri up for a surprise!
Check out the surprise from Seungi & Yeri's perspective (above), and from Sunmi & Han Chae Young's perspective (below)!