Billlie

Billlie (빌리) debuted on November 10, 2021 under Mystic Story with the mini album "the Billage of perception: chapter one" and title track "RING X RING". The group debuted with six members before Sheon — Girls Planet 999 contestant Kim Suyeon — joined later that month to complete the seven-member lineup: leader Moon Sua, Suhyeon, Haram, Tsuki, Sheon, Siyoon, and Haruna, with Tsuki and Haruna hailing from Japan. Their fandom is named Belllie've. Billlie's defining trait is "Billlie's mystery" — a serialized storytelling universe that threads every release together as chapters of one narrative. Experimental title tracks like "GingaMingaYo (the strange world)", "RING ma Bell (what a wonderful world)", and "EUNOIA" earned the group strong critical and cult-fan support, and Tsuki's "GingaMingaYo" fancam became a global meme in 2022. The group returned in October 2024 with "appendix: Of All We Have Lost", whose title track "remembrance candy" was produced with IU's participation, and released their first full-length album "the collective soul and unconscious: chapter two" in May 2026, led by "Zap". In the K-Pop Atlas graph, Billlie represents the concept-driven lane of the 4th generation — girl groups that prioritize narrative worldbuilding and musical experimentation over mainstream formula. As the first idol group launched by Mystic Story, the mid-sized agency founded by singer-songwriter Yoon Jong-shin, Billlie also marks an established non-idol label's entry into the idol industry.