TEEN TEEN (Hangul: 틴틴) was a 3-member boy group that debuted on September 18, 2019 under Maroo Entertainment. The members are: Jinwoo, Taeseung and Woojin, who are all former Produce X 101 contestants. In 2020, everyone in TEEN TEEN became part of the group GHOST9.

Pre-Debut
All members participated in Produce X 101, a boy group survival reality show. Their names was listed on the show as: as Lee Jin-woo (이진우), Lee Tae Seung (이태승) and Lee Woo-jin (이우진). Coincidentally, their future co-member in GHOST9, Choi Jun-seong, was on this show under Jellyfish Entertainment.
Woojin and Tae Seung were the first members to get eliminated out of the 3, which happened in episode 8 of the show when Woojin got rank 41 and Tae Seung 53. Both had previously got F rankings for the first evaluation. The highest rankings they had reached at the time of their elimination were 26 (Taeseung) and 41 (Woojin).
Three episodes later, in episode 11, Jin-woo got eliminated at the rank of 22. His highest rank at the time of his elimination was #4. As for his evaluations, he had gotten a C for the first one and a B for the second one.

Debut
The group debuted with the song "It's On You" (책임져요) on September 18, 2020. This song was the title track of their debut mini album, Very, On Top. This album also contained the songs:
"On Top (Intro)", "Be My Girl", "With Me" and "Stay".

In the middle of 2020, Maroo Entertainment announced that the TEEN TEEN members would become part of GHOST9, the new 9-member group of Maroo Entertainment, that debuted on September 23, 2020. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.