[2][3] Hoon originally debuted as a solo ballad singer under his real name and released an extended play Pure & Love with the title track "Bus" on September 9, 2009.

[7] He made his debut as a member of U-KISS through the group's fifth mini album Bran New Kiss which was released on March 30, 2011, with the title song "0330".

Later that year, it was announced that Hoon and Dongho would star in Super Action TV's Holy Land, a four-part movie about rebellious high school students.

[10] In May 2013, Hoon was cast in the Korean musical The Memory 2013 as Eunsoo, a role he shared with singer Brian Joo.

[16] On January 24, 2022, Hoon signed an exclusive contract with Tango Music where he also returned with his groupmates Soohyun and Kiseop.