After the 2-hour-plus concert, the North Korean leader and his wife shook hands with the pop stars and took pictures with them, the pool added.
Although it was the first time a North Korean leader ever watched a K-pop performance, experts said, Kim's apparent thumbs-up is not likely to lead to any change of policy toward South Korean cultural content in the near future.
Like the concert title, the performance had brought a "spring of peace" to the two Koreas, Kim was quoted as saying by KCNA, and expressed wishes for a "prosperous autumn".
"I reckon Kim also really wanted to see Red Velvet live, as many, many people all over East Asia do".
The trip was Kim's first foreign visit after resuming office in 2011.
The show's host Seohyeon of Girls' Generation, who performed with the North Korean art troupe in February in Seoul, welcomed the North Koreans to the show.
South Korean movies were often said to be especially taboo compared to Chinese films, according to a recent report by the InterMedia consultancy group, with North Koreans potentially facing prison time if caught.
The North Korean leader's face was slightly flushed in a group photograph with the performers distributed by North Korean state media, while in another, he was seen directly addressing members of Red Velvet, who command more than 4.6 million followers on Instagram.
In another sign of eased tensions, annual US-South Korean military exercises which got under way in the South yesterday will last for just one month compared to some two months normally.
Rock band YB performed next follows by K-pop girl group Red Velvet and then a performance by Choi Jin Hee - who is visiting the North for the fourth time - and Lee Sun Hee took place.
Kim also showed "great interest in the songs and lyrics (of South Korean singers) during the concert", Do Jong-hwan, Seoul's culture chief and the head of the delegation, told reporters.
A total of 26 songs were performed from 6:50 p.m.to 9 p.m., including Red Velvet's "Red Flavor" and "Bad Boy".
An official from the Unification Ministry said it was not known whether the North will air a recorded version of the show on its TV network, though a five-minute summary was shown Monday afternoon on the North's Korean Central Television.
On Friday, the two Koreas agreed to hold what will be the third inter-Korean summit following meetings in 2000 and 2007 at the border village of Panmunjom on April 27. He also said they should hold more such culture and art performances.
Roughly 300,000 South Korean soldiers were participating in the four-week Foal Eagle training alongside more than 11,500 USA troops, according to South Korea's Yonhap News Agency.
No U.S. aircraft carriers or nuclear submarines were expected to join the drills, Yonhap said.
The North Korean leader was seen watching the show and clapping while sitting in the center of the second floor seats, according to the show's cast members.
Republican Sen. Lindsey Graham of SC said he's glad John Bolton will serve as Trump's national security adviser going into talks with North Korea because of his "very healthy skepticism".
"We don't want to give him nine months or a year to talk and build a missile at the same time", Graham said on Fox News Sunday.
Seohyun performed "Greenish Willow Tree", a very popular North Korean song by late singer Kim Kwang-sook.