Ellie features in Seo Taiji's lead comeback single "Christmalo.win." (Seo Taiji Co.)

Child actress Ellie thanked K-pop legend Seo Taiji for a "happy time" during musical promotions for "Quiet Night," his ninth album, which came after a 14-year hiatus.

Ellie lent her voice for Seo's lead single "Christmalo.win," a portmanteau of "Christmas" and "Halloween," which topped all major Korean charts upon its release in mid-October. Actors Kim Soo-hyun and Shin Seung-hwan were featured in the music video.

Ellie shared a photo online in which she is posing affectionately with Seo's wife, actress Lee Eun-seong, and Park Shin-hye, reportedly a close friend of Lee.

From top: Ellie poses with Seo's wife Lee Eun-sung, and actress Park Shin-hye. (Facebook)

"Sadly, the nationwide concert tour for Seo Taiji's ninth album, 'Quiet Night,' has closed its curtains. It was such a happy time for Ellie," the caption read.

Seo, 43, wrote on his Facebook page Monday, "Ellie, thanks to you we were so happy during the ninth-album activities. Be healthy and let's be happy. See you."

Ellie, who has an American father and Korean mother, joined Seo on his first concert tour in five years. Seo, dubbed an eccentric musical genius, was an influential cultural icon in the '90s.

K-pop legend Seo Taiji held his first concerts "Quiet Night" in five years. (Seo Taiji Co.)

By Yoon Sarah (sarah356@heraldcorp.com)