On December 11, 2012, he released his first mini album "From Me to You" with self composed song "네게 난" as title track, which also marked his debut as songwriter.
[5] He made a guest appearance on one of his best friend, Kim Feel's showcase held at DiDimHall Hongdae on November 28.
Together with Go Hyung-suk, he helped B1A4's CNU composing the latter's first solo song, "음악을 취해 (Drunk with Music)", released on January 13, 2014.
[6] He also made appearance as Starship's team member in Mnet's Singer Game, and became a hot topic because of his performance and eye-contact strategy.
[7] He collaborated with former label mate d.ear composing "Taxi on the phone" for Topp Dogg's Kidoh, released on September 26.
His first release under Starship X is digital single "지워 (Erase)", which is a collaboration project with Sistar's Hyolyn featuring runner up of Show Me the Money season 3, Iron.
On April 4, 2015, along with Kim Feel, Mad Clown, and Hanhae he guested on 'Rolling Saypop Concert Vol.1 ELUPHANT Fly me to the moon'.
[16] Starship announced his enlistment the next month right after the release of "Love Line", surprising fans and public.
[18] On February 14, 2016, Jooyoung along with K.Will, Junggigo, and Brother Su released special Valentine song, "요리좀해요 (Cook for Love)".
[citation needed] On March 2, 2018, Jooyoung released a mini-album by the title of Fountain as a surprise to announce he had completed his service.