Kim Shi Hyun is an idol under Choon entertainment. His birth name is Kim Won (김원), but he legally changed it to Kim Shi Hyun (김시현).
He was set to participate in Produce 101 Season 2 (2017), but had to leave before the show started due to health issues. After the end of Produce 101 Season 2, he debuted with Jin Longguo as a duo under the name Longguo & Shihyun. His positions were vocalist, dancer and maknae.
He later participated in the survival show Under 19 (2019) and finished in 10th place, being one place away from debuting with the final line up. He was later announced to be debuting with the group WITZ.