On January 4, 2018,
Fantagio revealed that the group's comeback was being delayed indefinitely due to "the timing of the comeback, problems with the album preparation process, and the company's internal affairs". On January 11, the group released "Butterfly" as a digital single in support of the
2018 PyeongChang Winter Olympics. On February 1, after initial reports of "indefinite delay" in their comeback plans, the group confirmed in a press release for their reality show,
Weki Meki, What’s Up?, that they were preparing to release an album in late-February, continuing with their "girl crush" concept from their debut album. On February 6, Fantagio released a schedule for their new album, revealing the name as
Lucky. From February 6 to February 11, image teaser were revealed with pre-orders for the album starting on February 7. On February 12, the full track list was posted, revealing that the album will include 5 songs, including "Butterfly", previously released, and the title track "La La La". A day later, an album medley was released through the group's official YouTube channel. The EP was released through several music portals, including
MelOn in South Korea and
iTunes globally. == Commercial performance ==