Sistar would debut a sub-unit, Sistar19, with members Hyolyn and Bora. Their debut song, "Ma Boy", was released on 3 May. Sistar19 had their debut performance on 5 May and promoted throughout the month. Sistar returned on 9 August with their first studio album entitled So Cool. "So Cool" was the inaugural number one song on the Billboard Korea K-Pop Hot 100 chart after the chart's launch on 25 August. On 11 September, Sistar won their first "Mutizen Award" on Inkigayo. In early April, it was announced that Sistar was going to broadcast their "So Cool" comeback showcase globally in 41 countries. Their first mini album, entitled Alone, was released on 12 April and contained six songs produced by Brave Brothers. Their second mini album, Loving U, was released on 28 June. The EP contained the title track, "Loving U", produced by Duble Sidekick, one new song "Holiday" and remixes of the groups' past hits. 2013–2015: Give It to Me, summer hits and solo/duo activities Sistar19 released their first mini album, Gone Not Around Any Longer, and its title track of the same name on 31 January 2013. Their recording label, Starship Entertainment, announced on 16 May 2013, that Sistar will return mid-June, with another confirmation on 2 June, stating that they will be making their comeback with a second full album. On 3 June 2013, teaser photos featuring members Dasom and Bora were released. The following day, Sistar released photo teasers of all the members for Give It to Me and revealed that they will have a Moulin Rouge theme. A video teaser for "Give It to Me" was released on 6 June. Sistar's second studio album, Give It to Me, was released on 11 June with the title track of the same name. The album debuted at number four on Gaon Music Chart. On 26 October, Sistar represented South Korea at ABU TV Song Festival 2013 in Hanoi, Vietnam, performing "Give It to Me". Three more singles off the album: "The Way You Make Me Melt", "Crying" and "Bad Boy", as well as two promotional singles, were also released to promote the album. On 26 November, Hyolyn released her debut studio album Love & Hate, which reached number five on Gaon. On 5 June 2014, Sistar's label, Starship Entertainment, told Newsen that the group was working on a new album and would come back in the beginning of