Re:Blue

The group's comeback in South Korea was officially announced on December 17, 2012 via their concert Blue Night, held in Seoul. The mini-album's release date was scheduled for January 14, day of the group's third Korean anniversary and also third anniversary of the group's first Korean mini-album Bluetory.^[2] The first teaser was revealed on the group's website on January 3, 2013 with screencaps of the drama video teaser. The image also revealed 8 blank spaces (″___ _____″) that speculated if it was the name of the promotional track or of the mini-album's title.^[3] On January 7, the first video teasers were released. The teasers are emotional versions of the members expressing sadness or fury after a girl break up with them and says "I'm sorry". All individual video teasers were released on the same day.^[4][5][6][7] On January 9, a photo teaser was released. The photoshoot of the album was made in the streets of London. The group's agency, FNC Entertainment, revealed: "We worked hard to find a location that showcases London’s exotic aura. Although the filming was delayed due to the rainy weather, everyone passionately participated in the photoshoot."^[8] One day later, on January 10, the first music video teaser was released.^[9] On January 11, the second music video teaser was released.^[10] On January 14, along with the group's third Korean anniversary celebration, the mini-album and music video of "I'm Sorry" were released at the same time.^[11]

The mini-album is composed by six tracks, five Korean and an English track. A major part of the tracks were written by the member Jung Yong-hwa. The tracks "I'm Sorry", used as title track of the mini-album, and "Naram Namja" were written by Yong-hwa and Han Sung-ho and composed by Yong-hwa and Han Seung-hoon. "Coffee Shop" and "La La La" were written and composed by Yong-hwa. "Na Geudaeboda" was written by Han Sung-ho and Kim Jae-yang, who also composed the song along with the member Lee Jong-hyun. The English version of the song "Where You Are" was written and composed by Yong-hwa. The song was originally recorded in Japanese and first released on the Japanese album Code Name Blue as a bonus track of the CD+DVD edition.^[12]

The promotions of the song "I'm Sorry" started on January 18, 2013 on KBS' show Music Bank.^[13] They are also promoting on the shows Music Core,^[14] Inkigayo^[15] and Show Champion. Three songs of the mini-album were also performed during the first week of promotions: the song "Myself More Than You" on Music Bank on January 18, the English version of "Where You Are" on Music Core on January 19^[16] and "Coffee Shop" on Inkigayo on January 20. At the date, the song won 5 TV show awards, three on Show Champion: on January 30,^[17] February 6 and on February 13 and also won two on Music Bank on February 1.February 8^[18] The promotions ended on February 24, on SBS' Inkigayo.

On January 12, it was revealed that the album gained a lot of interest in South Korea and Japan, it topped the number one spot on Japan's Tower Records pre-order albums. The mini-album also surpassed the 100,000 mark only with pre-orders in South Korea.^[22] In its first day of release, the title track "I'm Sorry" topped all the South Korean music portal charts.^[23][24] The album also dominated the Gaon Charts for 2 weeks in a row.^[25]