Hwang Ji Hoon, aka Agent H enlisted as a non-commissioned officer in the Navy Special Warfare Corps at the age of 21. Five years later, he was discharged as a sergeant . During his military service, he was a member of the military's Underwater Demolition Team (UDT), aka a Korean Navy SEAL and also served as a sniper.

He is a model and the CEO of Kick the Hurdle Studio (KTHD), a broadcasting and media production company/studio/creator of YouTube Channels. Agent H's YouTube channel "Mission Possible" features military, exercise, & entertainment content videos. The channel has over 864 K subscribers and over 135M views.