Oh My Girl promoted the album with a series of televised live performances of "Closer" on South Korea's music shows.

"Closer" was positively received by several American music critics, making the K-pop top 20 year-end lists of Billboard and Noisey.

"Closer" was composed by Laura Brian and Sean Alexander, with Korean lyrics by Seo Ji-eum of Jam Factory.

Brian composed the chord progressions, melody, piano hook, and original English lyrics of "Closer", while Alexander did the arrangement.

It was originally written with an R&B beat for the American song market, and Alexander changed the instrumental to be more upbeat before sending it to contacts at the Key Artist Agency.

The last track, "Round About", is an uptempo R&B song with a swing rhythm, composed by the Swedish songwriting team with Korean lyrics by Kim Eana.

[5] The music video for "Closer" was produced by Yoo Sung-gyun of Sunny Visual, who also directed B1A4's "Solo Day" and "Sweet Girl".

It has a fairy tale and fantasy-inspired theme, called "magical, sad and beautiful" by Yoonjung Yi of BNT News.

Staff writers Jeff Benjamin and Jessica Oak said the song is a "whirlwind of dreamy, trance-pop from 2015's most promising new female act".