One Fine Day (어느 멋진 날; Eoneu Meotjin Nal) is the debut solo studio album by South Korean musician Jung Yong-hwa of CNBLUE.

As CNBLUE's promotions for their mini-album Can't Stop (2014) came to a close, the label announced plans for Jung to release a solo album within the year.

Jung began promoting the album by performing "One Fine Day" and the collaboration tracks on music chart programs across various television networks.

Jung embarked on his first series of solo concerts across Asia; select shows were recorded and released as live and video albums.

With CNBLUE's domestic promotions for its fifth mini-album Can't Stop coming to an end in March 2014, it was announced that Jung was expected to be releasing a solo album during the second half of the year.

[1] During the May 3 press conference for the band's 2014 Can't Stop Tour in Bangkok, Thailand, Jung revealed that he expected to collaborate with other musicians for the record.

[6] In crafting One Fine Day, Jung set out to produce a diverse album with a mix of various music styles, leading him to deliberately "pace out the recordings" of the tracks.

[10] In midst of filming TVN's television series The Three Musketeers, Jung was inspired by YDG's conveyance of endearment to his family on set to write the melody for "Mileage".

[12] In wanting to work with Verbal Jint, Jung expressed his admiration in the rapper's ability to craft acoustic hip-hop songs with sensible lyrics.

In suggesting the song title, Verbal Jint felt that it "would be applicable to all those whose shoulders are lagging from fatigue"; Jung "found it interesting and accepted it right away".

[13] Yoon expressed his desire to see CNBLUE flourish into a "true band" and decided that "it'd be great to give him [Jung] a hand".

In conceiving "Cruel Memories...", the pair sought to "create a boom among Korean men so that they go to karaokes in duos and sing their hearts out with this song, facing each other".

[14] Five months prior to meeting Jung, blues musician Peter Malick received a signed copy of CNBLUE's mini-album Can't Stop.

[16] In May 2014, Jung traveled to Los Angeles, California, to sing the South Korean national anthem "Aegukga" for Korea Night at the Dodger Stadium and to support baseball player Hyun-jin Ryu.

[19] In midst of recording One Fine Day, bandmates Kang Min-hyuk and Lee Jong-hyun would visit Jung and listen to the album tracks.

[25] "It's a simple image, a broken hearted man's dreamy rainbow tinted (as opposed to rose-tinted) gaze back to better times, helplessly watching his love falling ever further into the past, was it all just a dream?

[27][28] The artwork for the special edition of One Fine Day was designed by art collective StormStudios, its first time working with a South Korean musician.

[29] The designers originally planned to use the eye of a woman for the cover art, but were persuaded to use Jung's instead, under the basis that "such an intimate close up would make a paradoxically anonymous portrait shot".

[35] Initiated on the following day, the four artists he collaborated with were revealed on an individual basis, beginning with hip hop musician and actor YDG.

[38] Continuing through January 11–13, the collaborations revealed were rapper Verbal Jint on "Energy", rock musician Yoon Do-hyun of YB on "Cruel Memories...", and Singaporean singer JJ Lin on "Checkmate", respectively.

[43] One day prior to the release of the album, Jung held a private showcase at the Maria Callas Hall in the Daechi-dong neighborhood of the Gangnam District in Seoul, South Korea.

[45] On January 22, Jung began promoting "One Fine Day" by performing the song on weekly music chart shows.

Along with the aforementioned song, the album also includes the bonus track "Kimi wo Suki ni Natte Yokatta" with lyrics written by musician Takuro of rock band Glay.

Pop music critic Kim Young-dae of Ize magazine stated that the lead single was "not fundamentally different from his previous works" with CNBLUE, but the other album tracks "attest to the fact that Jung Yong-hwa's songwriting capability has stepped up to a standard".

He noted that Jung "organically amplifies the momentum" of his songs "without an obvious structural mechanism shows definite signs of growth".

However, he also felt that Jung still faced shortcomings in his compositions, describing that the refrains to his songs "walk a thin line between the familiar and the predictable".

She described the album as "largely easy on the ears", citing the familiarity between One Fine Day and the pop rock sound of CNBLUE.