He then released the self-produced 2nd mini album, Teenager, which contained six self-composed tracks on June 26, 2014.Jung had his Taiwan fan meeting in 2013 and followed it with his first overseas showcase in Taipei in July 2014.
He hosted his own radio program titled MBC FM's Jung Joon-young's Simsimtapa (2014) and made his big screen debut in Love Forecast (2015).
Since 2015, Jung is the lead vocalist of rock band Drug Restaurant, previously known as JJY Band, Since his official debut with the release of 1st Mini Album in October 2013, Jung has won the "New Male Solo Artist" award for its title track "이별 10분전 (The Sense of an Ending)" at the 3rd Gaon Chart K-Pop Awards.
Throughout the final stages, he stuck to rock style as his only musical style.
He was repeatedly suggested to that he needed to try a different genre of music, such as ballad, by the judges.
Jung had a lonely childhood in many different countries but he learned to speak five different languages such as English, Mandarin, Korean, conversational Japanese, and Tagalog.
He couldn't enroll in a regular school due to frequent moves.He performed the self-written "하루만 (I’m Nobody)" at the Pretty Man OST Japan Concert in July 2014.He held a concert tour in China in November 2014 and performed in Beijing, Shenzhen, and Shanghai.His covers that represented his rock style were "매일매일 기다려 Waiting Everyday"(Tee Sams), "Bed of Roses"(Bon Jovi), and "Outsider" "(Bom-Yeoreum-Gaeul-Gyeoul 봄여름가을겨울) Though he was eliminated in the six stage of the semi-final as Top 3, Superstar K4 allowed the public to recognize his musical style.He even mentioned that "Superstar K4 was the turning point in my music career.As a struggling musician, he modeled for several online shopping malls.