It was released on April 30, 2021, through JYP Entertainment, as the lead single from the group's fourth extended play, Guess Who.

Musically, it is a hip hop, trap and dance track with its title referring to the popular party game Mafia, and a metaphor for aiming to be caught in a relationship.

The accompanying music video, directed by Bang Jae-yeob, sports a dark atmosphere and depicts Itzy performing fierce choreography on various glamorous sets.

[3] Starting from April 13, the group's label uploaded various teasers for each member on their respective social media accounts.

[8] "In the Morning" was released for digital download and streaming as the lead single from Guess Who on April 30, 2021, by JYP Entertainment.

[12] The song is inspired by the mafia game, the werewolves, where the main character has to hide their emotions and act very differently.

Writing for Forbes, Jeff Benjamin described the song as a "sinister" hip hop track with "one of their boldest and most experimental sounds yet".

[13] Divyansha Dongre from the India version of Rolling Stone noted that the song "sees the group explore various new vocal styles".

[2] In a mixed review, Sofiana Ramli of NME felt that the track "sounds like almost every other EDM-oriented song that's been churned out in K-pop today".

[14] Joshua Minsoo Kim of Pitchfork found that, although their debut "established the quintet as a massive new force in the industry", their latest release, "In the Morning", was the biggest offender from Guess Who, commenting that in the song "there's a Cardi B lilt in the verses, but it otherwise feels like Blackpink without the stadium-sized grandeur".

[16] By doubling their total number of appearances, the band became the second-ever girl group from South Korea to hit the ranking more than once.

[26] The music video opens with Ryujin in a cropped jacket and pleated skirt posing among mannequins in a fashion shop.