Bluetory

After being scouted by FNC Music's casting director, Jung Yong-hwa, Lee Jong-hyun, and Kang Min-hyuk met while auditioning for the agency. The three kept in contact before being accepted by the record company.[1] FNC Music decided to send CNBLUE to Japan "where the idea of a band is more recognized"; the band saw it as an opportunity to "improve on our skills".[1] The quartet initially debuted there under AI Entertainment in 2009, where it released its first two independent mini-albums Now or Never and Voice.[2][3] The band would perform on the streets and in small venues throughout the country.[4] Unable to speak Japanese, the members learned the language "in order to survive out there".[1] In late September, bassist Kwon Kwang-jin left the band due to "personal reasons" and was replaced by Lee Jung-shin later that year.[1][5]

During this time period, Jung was cast in Seoul Broadcasting System's (SBS) television series You're Beautiful,[6] where he played guitarist Kang Shin-woo in the fictional band A.N.Jell.[1] The drama saw popularity in international markets, which fostered the growth of his popularity.[4][7]

Musically, Bluetory is a pop-rock record.[8] Jung described it as being an alternative rock mini-album, which also incorporated hip hop, rap, and balladry.[1] Originally sung in English for the band's Japanese mini-albums, the tracks "Y, Why...", "Now or Never", and "I Will... Forget You..." were re-recorded in Korean for inclusion on Bluetory.[1][9] "Y, Why..." encompasses a "refreshing" guitar, while the latter was classified as a modern rock song with an "explosive" guitar in the chorus.[8] Frontman Jung identified the lattermost track as the first ballad in CNBLUE's catalog.[9]

CNBLUE was dubbed "the second" F.T. Island since its inception.[10] In early December 2009, Jung first revealed that CNBLUE was set to debut in South Korea "early" the following year.[7] On January 5, 2010, CNBLUE's debut was announced to be on January 14.[11] In addition to video teasers, each member was accompanied by a word that made up the acronym BLUE, which was meant to portray their individual images. The first 35-second teaser was released on January 7, which revealed Lee Jong-hyun and the word "burning".[12] The following day, Kang Min-hyuk and the word "lovely" were revealed.[13] The video teaser for Lee Jung-shin with the accompanying word "untouchable" was published on January 11.[14] The fourth and final teaser featuring Jung with the word "emotional" was revealed one day prior to the release of the mini-album.[15]

Bluetory and the lead single "I'm a Loner" were concurrently released on January 14.[16] The band partook in an album showcase later that day at the Textile Center in the Samseong-dong area of Seoul.[17] On the following day, CNBLUE began promoting "I'm a Loner" by performing the song on weekly music chart shows, beginning with Korean Broadcasting System's (KBS) Music Bank and SBS's Inkigayo.[18][19] On the January 29 broadcast of Music Bank, CNBLUE ranked number one on program's music chart, earning the band its first music show win.[20] CNBLUE won the Mutizen Song award on Inkigayo two days later, the band's second and final win.[21] At the time, CNBLUE's initial win two weeks into its debut was unprecedented.[22] It held the record for shortest amount of time to win a music show award after debut until Winner won its first music show on August 17, 2014, five days into its debut.[23]

Performing only in Japan up to its debut, CNBLUE also sought to execute a series of guerrilla concerts in South Korea.[24] The quartet decided to go in order of its acronym for the members' individual images (BLUE). The first performance was decided by guitarist Lee; dubbed the "Burning Street Concert", it took place in Hongdae, Seoul.[9]

On the chart dated January 10–16, 2010, Bluetory debuted at number one on the Gaon Album Chart.[25] It went on to top the chart for a second consecutive week.[26] By the end of the year, the mini-album sold 77,183 copies and was ranked at the 12th best-selling album in South Korea.[27] In the four years that followed, the record sold an additional 41,782 copies in the country, accumulating sales of 118,965 in total.[upper-alpha 1]

• List of Gaon Album Chart number ones of 2010