On May 2, 2018, Starship and Fantagio announced the formation of the special unit group called WJMK. The unit consists of WJSN's SeolA and Luda, and Weki Meki's Yoojung and Doyeon. They debuted with a "cutie crush" concept.[2]
SURPRISE U(Kim Hyun Seo, Yoon Jeong Hyuk, Eun Hae Seong, Ji Geon Woo) • Baek Yoon-sik • Cha Eun Woo • Choi Jun-young • Choi Yoojung • Choi Yun-la • Chu Yejin • Han Gi-chan • Jin Su-hyun • Joe In • Jung Min Gyu • Kang Hae-lim • Kim Do-gyung • Kim Doyeon • Kim Mi-hwa • Kim Nu-rim • Lee Jong-uk • Lim Hyun-sang • Moon Yoo-bin • Ong Seong Wu • Park Ye-rin • Jung Min Gyu