Despite his father's opposition to him entering show business, Chun began his career as a backup dancer and debuted in 1996 as one-half of the dance-pop duo Hamo Hamo (ko) with Lee Sung-jin, while Noh Yoo-min and Moon Sung-hoon served as their backup dancers.

The group had their big break with the 2003 single "Hit Song", composed by Chun, and won their first ever #1 on a music program.

[3] However their future plans of a comeback were put on hold due to Lee's fraud and gambling investigation and they eventually agreed to go their separate ways.

After NRG's disbandment, Chun was the only member who remained in the entertainment industry; Noh and Moon had both entered the business world while Lee stayed out of the public eye due to his legal troubles.

On October 22, 2016, Chun reunited with Noh Yoo-min and Lee Sung-jin to announce that NRG would be returning the following year to celebrate the 20th anniversary of their debut.