Siwoo

On June 3, 2020, Jimin was introduced as a participant in the CJ ENM and Big Hit Entertainment's then upcoming survival show I-LAND. On the first episode, he performed "Shoot Out" by MONSTA X, along with Sungchul and Jaebeom and was unable to enter "I-LAND". On the seventh episode, he was eliminated from the show and was unable to participate in Part 2.

On May 29, 2021, JM was officially revealed as a member of Bluedot Entertainment's then upcoming boy group JUST B. On June 30, he then debuted in JUST B with the release of their debut mini album Just Burn. On July 16, 2024, it was announced that JM had changed his stage name and would be going by Siwoo from now on.