His father, Chang Sŏng-man (1932–2015), was a pastor, educator who was the former chancellor of Dongseo University and also a politician served as an MP of Democratic Justice Party, the predecessor of LKP, from 1981 to 1988 and was also the Deputy Speaker of the National Assembly from 1987 to 1988.

[1] He also shortly served as the deputy parliamentary leader of Grand National Party, the predecessor of LKP, in June 2009.

[9] During the political scandal in the late 2016, Chang was one of hearing members from the Saenuri Party[10] (LKP since February 2017) along with Kwon Seong-dong and Hwang Young-cheul.

[12] On 22 March 2018, Chang provoked a controversy when he called the police as "government's hounds infected with rabies" after they launched an investigation related to Kim Ki-hyun,[13][14] the then Mayor of Ulsan, who was also a member of the LKP.

[16] On 7 September 2019, NO:EL was caught by police nearby Mapo District in Seoul after his car hit a motorcycle.

[18][19] Chang apologised for this issue,[18][19][20] however, the Justice Party urged him to resign as an MP should it is proven as true.