[2] The quartet was formed through the reality competition program Build Up: Vocal Boy Group Survival, aired in the first quarter of 2024.

[3] Prior to the One Team Mission of the show, Sunyoul was previously hailed as the top tier among the contestants with the privilege to organize a four-member group.

He recruited Kang Ha-yoon, Wumuti, and Choi Su-hwan as team members to form Waterfire.

Sunyoul is a member of the boy group Up10tion and appeared as a contestant in King of Mask Singer and Mr.

[6] In 2015, Wumuti was among the winners of a Chinese survival reality show Super Idol, and debuted as a member of SWIN.