Standing on top of a green grass hill, the main stage decor, a children's choir opened the K-pop sibling duo AKMU’s two-day concert singing “Last Goodbye.”

AKMU then appeared on a lift in a navy suit and dress to perform “Every Little Thing” with a live band and a string orchestra.

The K-pop duo was welcomed by 10,500 people in the audience holding green fan lights that shined like fireflies glowing on summer evenings.

Sunday’s show was the last day of AKMU’s two-day 10th-anniversary concert “10VE” at the Kspo Dome in Seoul.

With musical actors taking part in AKMU’s performances adding more emotion and liveliness to the stage, the concert felt like a musical.

“I didn’t want you to come to our concert to just listen to us sing. Instead, I wanted our concert to be like a picnic that you can enjoy peacefully and go back home filled with love,” said Lee Chan-hyuk of AKMU.

Chan-hyuk had a solo stage performing “Bench” during which he had a chance to show off his dancing skills.

Lee Su-hyun of AKMU then performed “Re-bye” alone holding a feather fan.

She added some acting and altered the song to make it jazzier.

In the setlist of 21 songs, AKMU included many tracks from its debut album “Play” released in 2014.

“We wanted to take you guys back 10 years. Our concept for the debut album was fairies living in a forest. That is why the set is a scene from a fairytale,” said Su-hyun.

Su-hyun then sat down in front of a piano and Chan-hyuk took out his acoustic guitar.

“We used to play like this when we were young living in Mongolia,” Su-hyun told her brother.

The siblings then dazzled the audience singing “Time and Fallen Leaves” and “How can I love the heartbreak, you’re the one I love” while playing their instruments.

For the second part of the show, AKMU appeared inside a cave under the green hill.

“Hi, we are the acoustic duo AKMU,” said AKMU, just like how they introduced themselves when starring on SBS’ audition show “K-pop Star Season 2" in 2012.

The duo performed a medley of singles “Crescendo,” “On the Subway,” “The Love of Foreigner” and “Little Star.”

Near the show's end, K-pop soloist IU made a surprise appearance as a guest performer.

“It’s an honor to be invited to AKMU’s 10th anniversary concert. I was their guest performer for their first-ever standalone concert as well, so this is very meaningful. I want to congratulate them for becoming one of the best South Korean musicians,” said IU.

IU performed “The Meaning Of You” and “Blueming.”

Su-hyun also performed an unreleased song “Remember” for the first time on stage.

“This is a song that I made thinking about my younger self. I am happy I get to sing this song in front of you guys,” said Su-hyun.

The song is about a girl chasing her dreams and the older Su-hyun telling her younger self that she has the right to be happy.

The concert reached its climax when AKMU performed “Green Window” and “200%.”

“This will be an unforgettable concert for us. Through this concert, we wanted to look back on our lives which had their ups and downs. The last song reminisces on our childhood,” said Chan-hyuk.

AKMU wrapped up the concert with “Will Last Forever.”