Who Are The Main Actors In My Younger Boss?

As a drama addict who’s watched way too many workplace rom-coms, 'My Younger Boss' stands out because of its casting choices. Park Seo-joon was born to play roles where he’s equal parts infuriating and endearing, and his younger boss character is no exception. Kim Da-mi complements him perfectly; her character’s dry wit and eye rolls are iconic. But let’s not forget the unsung heroes—the office ensemble! There’s this one scene where the whole team tries to cover up a printing error, and the panic-acting is so over-the-top it’s genius. Special shoutout to the actor playing the IT guy (I think it’s Ahn Jae-hong?), whose deadpan tech support one-liners are low-key the funniest part of the show.

The romantic tension between the leads is chef’s kiss, but what really got me was the mentorship dynamic with the older female director (played by Kim Sun-young). Her scenes with Park Seo-joon add depth to his character’s growth. Casting directors nailed it by picking actors who could switch between slapstick and sincerity on a dime. Even the villainous rival, played by that guy from 'Stranger' (Yoo Jae-myung, maybe?), is so good at being smug you love to hate him. The show’s success is 80% thanks to this ensemble’s ability to make tropes feel fresh.

Park Seo-joon and Kim Da-mi carry 'My Younger Boss' with this hilarious odd-couple energy. He’s all flustered arrogance as the youngest boss in company history, while she’s the unimpressed employee who sees right through him. Their bickering scenes are pure gold—like when he tries to fire her and she just laughs in his face. The supporting cast adds so much flavor too, especially the office gossip crew and the perpetually exhausted HR manager. It’s one of those shows where even small roles leave an impression, like the barista who ships the leads harder than the audience. The actors’ chemistry makes the predictable plot feel brand new.

I just finished rewatching 'My Younger Boss' for the third time, and the cast is honestly one of its biggest strengths! The chemistry between the leads is electric—especially Park Seo-joon, who plays the charismatic but slightly chaotic younger boss with this perfect mix of arrogance and vulnerability. His comedic timing is golden, especially in scenes where he’s trying to assert authority while secretly panicking. Then there’s Kim Da-mi as the no-nonsense employee who slowly melts his ego; her deadpan expressions kill me every time. The supporting cast shines too, like Lee Byung-hun as the eccentric CEO who steals every scene he’s in. It’s one of those rare shows where even minor characters feel fully fleshed out, like the gossipy office mates or the rival boss played by Yoo Jae-myung. The actors all bring such distinct energy that the workplace dynamics feel hilariously real.

What I love most is how the cast balances humor with heartfelt moments. Park Seo-joon’s subtle shifts from cocky to insecure make his character deeply relatable, and Kim Da-mi’s quiet strength avoids the 'manic pixie dream girl' trope. Even the romantic subplot with the café owner (played by Jung Hae-in) adds warmth without overshadowing the main storyline. The actors’ Instagram BTS posts show how much fun they had filming, which totally translates on screen. If you haven’t seen it yet, binge it for the performances alone—they turn a typical office rom-com into something special.