A North Korean delegation led by leader Kim Jong-un's sister Yo-jong had dinner with Cheong Wa Dae chief of staff Im Jong-seok on Sunday before watching the North's Samjiyeon Orchestra perform in Seoul.
Kim Yo-jong sat next to President Moon Jae-in during the performance in what was their fourth meeting during her three-day visit.
The orchestra performed a medley of songs, with bandleader-cum-apparatchik Hyon Song-wol taking the stage to sing the finale, "Baekdu and Halla Are My Nation's."
After Hyon's song ended, Unification Minister Cho Myoung-gyon jumped to his feet and shouted "encore!" Seo-hyun of girl band Girls' Generation unexpectedly appeared and joined the North Korean performers in singing "Our Hope is Unification," which drew thunderous applause. Seo and one of the North Korean singers embraced.
Kim Yo-jong and the North Korean delegation flew out of Incheon International Airport aboard Kim Jong-un's personal plane that night, with the unification minister seeing them off at the airport.
The dinner was hosted at a hotel in Seoul just across the street from the concert venue.
Kim Yo-jong said at the banquet, "I am not really a good speaker. I honestly did not think I would come here at such short notice and expected something very different. But I found that we share many similarities."
Earlier, the North Korean delegation had lunch at the Walkerhill Hotel in Seoul with Prime Minister Lee Nak-yon.
Moon and Kim Yo-jong spent more than 10 hours together in meetings, at the opening ceremony of the Winter Olympics, lunch at Cheong Wa Dae, an ice hockey match of the inter-Korean women's team and the concert.