[3] Many rumors about whether the singer will release his new album floated since the beginning of this year until it was finally announced that Seo would make his comeback in October 2014.

[4][5] On August 28, 2014, two months before Seo's comeback, seven screen doors in Seoul Subway Line 2 carried the following message, "We still are young.

[4] Starting from his comeback concert "Christmalowin" held at Seoul Olympic Stadium on October 18, the artist began promoting his ninth studio album.

"[7] "Sogyeokdong" (Hangul: 소격동), produced in secret collaboration with South Korean singer-songwriter IU, is a pre-release single for the album Quiet Night.

[11] According to Seo's agency, the singer planned this collaboration project under the theme of a sad and beautiful story which happened in Sogyeok-dong of 1980s, from the standpoints of a woman and a man, through two different versions of songs and music videos.

"[21][23] The theatrical version of its music video features child actresses Ellie (whose voice can be heard at the end of the song) and Kim Soo-hyun, and actor Shin Seung-hwan.

[26] Two days prior to the album's release, Seo held his comeback concert "Christmalowin" at Seoul Olympic Stadium, in support of Quiet Night.

[32][33][34][35] He also performed "Fighter of the Forest" (Korean: 숲 속의 파이터; RR: Sup Sogui Paiteo), alongside the singles preceding the album, on Mnet's M!