and was also her dance partner for the music video and live performances of its lead single "Choco Chip Cookies".

[8][9] On December 8, Kard revealed that their first "hiDDen card" member would be their labelmate Heo Young-ji, and further elaborated that Youngji would be active only in the first release of the group's "Kard Project", wherein they will release three project singles each with their own "hidden card" feature before their official debut.

Following this development, it was revealed that all content for Kard's final project single titled "Rumor", including its music videos, will be produced in collaboration with LG Electronics G6.

[23] "Rumor" was then released on April 24, with the song's music video featuring Korean choreographer Z.Sun as the group's third "hidden card" member.

Somin and Jiwoo joined Super Junior to perform the song on various Korean music programs.

[39] Kard then held an Asia-wide tour spanning four countries: Singapore, Taiwan, Hong Kong and the Philippines.

[41] On April 14, 2018, the group met local fans through their 2018 Wild Kard Tour in the Kasablanka Hall in Jakarta, Indonesia.

[43] The EP debuted and peaked at number 7 on the Gaon Album Chart for the week ending July 28, 2018.

[48] The following month, Kard performed at the 2019 Dream Concert held at the World Cup Stadium in Sangam-dong, Seoul on May 18.

Following the success of the single which peaked at number three on the Billboard World Digital Song Sales chart, Kard debuted on the Billboard Social 50 chart, ranking at number 41 on its tally dated on October 5 as they experienced a 39% increase in Twitter mentions and a 457% increase in YouTube subscribers.

[53][54] The following month, on November 6, Kard appeared at the Young Hollywood studio in Los Angeles, talking about their comeback song "Dumb Litty", and playing the Mystery Box Challenge game.

[57] Additionally, its eponymous title track reached a peak position of number 8 on the Billboard World Digital Song Sales Chart.

[69] On March 23, 2023, it was confirmed that Kard will be making their comeback in April 2023 and has recently finished filming their new music video.

Kard's brand of K-pop has been described as "undeniably trendy", with their discography focusing on contemporary house and dancehall vibes, which Billboard has referred to as something that is "pulled directly from Top 40 charts".

The group was also noted for their reggaetón and moombahton styling that resonated with international K-pop fans, which was stated by Billboard to be one of the primary reasons why they were able to tour throughout North and South America even prior to releasing their first mini-album.

[71] A notable shift in Kard's sonic style was first seen through the release of their single "Dumb Litty", which incorporated dancehall alongside synth, trap, and EDM.

[72][73] Following the release of their fourth EP, Red Moon, member BM has dubbed moombahton as "a symbol of Kard".

[77] Billboard magazine has described Kard to be "one of the most successful co-ed K-pop acts to ever exist" which was seen when their debut EP landed at number 3 on the World Albums Chart.

Due to their lack of promotions in their country of origin, a Korean broadcasting station official once told the members of Kard that they were "like a fictional group [to him]".