Originally a five-member boy band consisting of Chun Myung-hoon, Lee Sung-jin, Noh Yoo-min, Moon Sung-hoon, and Kim Hwan-sung, NRG debuted in 1997 and underwent sporadic periods of activity and hiatus between 2000 and 2008 before going on an extended hiatus.

Lee Sung-jin and Chun Myung-hoon originally debuted in 1996 as duet under the name HamoHamo and released one album with moderate success from the singles, "Papillion" and "Pangpang".

NRG's second album Race was released that same year, and featured more high energy dance songs like "Messenger", selling over 300,000 copies in South Korea.

[2] NRG became the first South Korean musical group to actively market themselves in China, where they have sold over 100,000 copies.

[5] In August 2001, NRG held their first concert in Korea, which also served as a tribute to Kim Hwan-sung.

[6] 1 year and six months after the release of Sorrow, NRG returned with their fifth album Hit Song in February 2003.

The title track placed 4th in the pop charts as the World Cup neared, and was fitting for the occasion.

Soon afterward, Moon announced his departure for unspecified reasons and remained out of the public eye for over a decade; he appeared on the SBS show Star Couple (ko) with his wife in 2012 and revealed that they had a son, although they have since divorced.

[15] Noh ventured into business and made sporadic appearances on various variety shows, including Handsome Boys of the 20th Century which starred Chun and four other fellow first-generation idol group members.

[1] On September 27, 2017, it was announced NRG would participate in the 2017 Dream Concert, marking their first performance since their disbandment 11 years ago.