JBJ (an acronym for Just Be Joyful) was a six-member project boy group under LOEN Entertainment. Similar to I.B.I, the group consists of Produce 101 Season 2 contestants who didn't made to the top 11 (ranking 20–30) and was formed by LOEN due to fan requests. They officially debuted on October 18, 2017 with their first mini album Fantasy. The group disbanded on April 30, 2018 following the end of their 7-month contract.
|Taehyun (태현)||Leader, Main Dancer, Lead Vocalist, Rapper|
|Kenta (켄타)||Main Vocalist, Lead Dancer|
|Sanggyun (상균)||Main Rapper|
|Longguo (용국)||Main Vocalist|
|Hyunbin (현빈)||Lead Rapper|
|Donghan (동한)||Lead Vocalist, Lead Dancer, Maknae|
- New Moon (2018)
- Roh Tae Hyun is a member of HOTSHOT, previously known by the stage name Kid Monster.
- Kim Sang Gyun was a member of ToppDogg under the stage name A-Tom.
- Jin Long Guo is a member of Longguo & Shihyun under the name Longguo.
- Contestant Kim Tae Dong was slated to become the seventh member but conflicts with his agency, MAJOR9, had prevented him from joining.