On January 1, 2021, New Year's Day, Stray Kids released the video Step Out 2021, consisting of the group's achievements in 2020, and 2021's to-do plan, including their project called Season Song.

[6] In 2021, the group made history after participating and won the Mnet competitive reality television show Kingdom: Legendary War,[7] and releasing their second studio album Noeasy on August 23 with the lead single "Thunderous", which received an important musical success.

[14] The Christmas-themed ballad second track, "24 to 25", is about wanting to spend time together from December 24 to 25, especially with their fans, called Stay, driven by a "calm" guitar sound.

[10][11][21] The second expresses the members tying a bow on their necks and wearing Christmas-themed outfits, surrounded by wrapped presents and a Christmas tree in the background.

[22][23][24] The official track listing was posted on November 19, serving "Christmas EveL" and "Winter Falls" as a double lead single on the record.

[29] An accompanying music video for "Christmas EveL" was premiered alongside the single album release,[30] "Winter Falls" the next day,[31] and "24 to 25" on December 6.

[32] Although there is no promotion at the music shows, "Winter Falls" was given a debut performance at 2021 SBS Gayo Daejeon on December 25, alongside "Thunderous", arranged in the Christmas version.

[35][36] Writing for NME, Rhian Daly rated Christmas EveL four out of five stars, and said that aside from the English version of "Domino" that provides a "fiery end to the record", there is a "Christmassy atmosphere that runs neatly through the rest of the tracks".