After charming audiences with his role in When Life Gives You Tangerines, Park Bo Gum returns with a dramatic transformation in the action-packed JTBC series Good Boy. 

The makers of the K-drama recently unveiled a teaser that hints at a thrilling mix of adrenaline, emotion and second chances as Olympic athletes trade gold medals for police badges.

The 50-second teaser kicks off on a triumphant note, spotlighting each character’s athletic glory. 

Park Bo Gum is introduced as boxing champion Yoon Dong Joo, Kim So Hyun stuns as a sharpshooting prodigy, and Lee Sang Yi’s fencing finesse is on full display. Joined by Heo Sung Tae and Tae Won Suk, the team is a force of sporting excellence.

But the teaser quickly pivots. Gone are the cheers and confetti – instead, viewers are plunged into a world of broken dreams and odd jobs. 

From a restless Dong Joo sitting alone in a rundown car to a mascot-suited discus thrower trudging through monotony, the visuals reflect the weight of dashed hopes. 

As these former athletes are roped into a rookie cop program, their camaraderie begins to grow – and so does the danger. A shadowy villain from Inseong City looms large, pushing them to revive their long-dormant skills. 

Dubbed the “Goodvengers,” this unlikely squad rises to meet the chaos head-on, with Park Bo Gum’s defiant closing line – “The round isn’t over until we’ve taken down our opponent” – delivering the perfect punch.

Directed by Shim Na Yeon and written by Lee Dae Il, Good Boy premieres May 31 at 10:40 p.m. KST on JTBC and globally on Prime Video.