Their debut EP First Love was released on March 19, 2015, with five group members: Seunghee, Yujin, Seungyeon, Sorn, and Yeeun.

From 2020 onward, Cube halted CLC promotions and the members have embarked on individual music, acting, and modeling careers.

[2] The five original members of CLC (Seunghee, Yujin, Seungyeon, Sorn, and Yeeun) made their first appearance as back-up dancers for G.NA in 2014.

Before their official debut, the group began to gain publicity through street performances they held to raise money for children with disabilities.

[13][14] On April 16, CLC released a digital single titled "Eighteen", described as a song about teenage love influenced by 1960s/70s motown and 1980s synthpop.

[23] On February 29, a short version of the "High Heels" music video that included Elkie but omitted Eunbin was released.

The album includes the Japanese version of "Pepe", "First Love", "Like", "High Heels", and a cover of Kylie Minogue's "I Should Be So Lucky".

[27] On May 12, CLC launched their official Naver V App channel, followed by a broadcast of Eunbin's first live appearance with the group.

[28][29] The group released their fourth Korean EP Nu.Clear on May 30, with the title track "No Oh Oh" written by Shinsadong Tiger.

[39][40] The EP contains six tracks including the EDM/trap lead single "Hobgoblin" (도깨비), co-written by Seo Jae-woo, Big Sancho, Son Yeong-jin, and HyunA.

The album title is portmanteau upon the words "prism" and "free", describing the group's musical and conceptual direction for this EP.

[49] The group released the digital single "To The Sky" on February 1, 2018, as a pre-release track of their upcoming EP.

[66] On August 20, CLC released a new logo, a more simpler and mature monogram with the 'L' being stylised to look like an upside-down '7' in reference to the seven members.

She said she had not been paid for her acting activities, and that Cube Entertainment had already stopped their "developmental support" of CLC, putting the group's future on hold.

[73] On March 9, Seunghee, Yeeun and Seungyeon released an OST titled "Another Level" for the Korean web drama Be My Boyfriend.

[75] On June 7, SPOTV News reported that Yujin would be participating in Mnet's survival show, Girls Planet 999.

[76] Later, on August 13, 2021, during an interview Yujin gave during the show, she mentioned while tearing up that she had been told by the company that "CLC will no longer be having group activities".

[77] On October 22, during the finale of Girls Planet 999, Yujin ranked 3rd and secured her spot as a member and leader of the debuting group, Kep1er.

[85] On March 7, while promoting her single "Not A Friend", Sorn commented on the group's status on a TikTok live stating that they "did not disband" and "right now everyone's just doing their own thing."

[86] Prior to their debut, the five original members of CLC busked to raise money for children with developmental disabilities.

[5] Profits from their b-side track, "Sharala", from their debut EP, First Love, were also donated to developmental disabilities charities.