You know that feeling when a show just clicks? It’s not just the writing or the high-budget sets. It’s the people. When we talk about the cast of 100 Days My Prince, we aren't just looking at a list of actors who did a job; we’re looking at a lightning-in-a-bottle moment for tvN. Back in 2018, this show became one of the highest-rated cable dramas in Korean history. Why? Because the chemistry was visceral.
Honestly, the premise sounds like every other "amnesia" trope you’ve seen a thousand times. A cold prince gets attacked, loses his memory, and ends up as a useless peasant married to a spunky commoner. Boring, right? Wrong. Because Do Kyung-soo (D.O.) and Nam Ji-hyun decided to turn those tropes into something remarkably human.
The duo that carried the crown
D.O. is a fascinating actor. If you’ve followed his career from his early days in EXO to his gritty role in Swing Kids, you know he has "acting eyes." In this drama, he had to play two people: Lee Yul, the sharp, traumatized Crown Prince, and Won-deuk, the man who couldn't do a single chore to save his life.
His delivery of the catchphrase "I feel very uncomfortable" became a literal meme. It wasn't just funny; it was a masterclass in deadpan comedy. He didn't play Won-deuk as an idiot. He played him as a prince trapped in a body that didn't know how to be poor. That nuance is why people still rewatch his scenes today.
Then there’s Nam Ji-hyun. She’s a veteran. Having started as a child actress, she knows how to ground a scene. As Yeon Hong-shim, she wasn't just a "love interest." She was the engine of the plot. Her timing? Impeccable. She had to balance the tragedy of her character’s hidden past with the absurdity of teaching a grown man how to twist rope.
The spark between them wasn't forced. It felt like two people actually annoyed with each other, which—as any married couple will tell you—is much more realistic than immediate star-crossed lovers.
The supporting players who stole the spotlight
We have to talk about Kim Seon-ho. Before he was the "Good Boy" in Start-Up or the charismatic lead in Hometown Cha-Cha-Cha, he was Jung Je-yoon in this show. He played the hidden official with "face blindness," which added a layer of vulnerability to his sharp intellect.
🔗 Read more: The Name of This Band Is Talking Heads: Why This Live Album Still Beats the Studio Records
His bromance with D.O.’s character was, frankly, better than the romance at times.
Je-yoon was the bridge between the palace politics and the village life. Seon-ho’s ability to switch from a goofy smile to a look of intense longing for Hong-shim gave the second-lead syndrome a whole new meaning. It's rare to see a character who is genuinely smart but also okay with being the butt of the joke.
The villain we loved to hate
Cho Seong-ha as Kim Cha-eon. Wow.
If you want to see a masterclass in playing a "power-hungry Left State Minister," look no further. He didn't scream. He didn't twirl a mustache. He just existed with a cold, terrifying stillness. Every time he stepped onto the screen, the temperature of the scene dropped. His relationship with his daughter, the Crown Princess (played by Han So-hee), was one of the most tragic and messed-up dynamics in the whole series.
Speaking of Han So-hee, this was a massive breakout for her. Long before The World of the Married or My Name, she was the "Ice Queen" Princess So-hye. She was trapped. She was pregnant with another man’s child while married to a prince who hated her. Han So-hee managed to make you pity a character who was technically an antagonist. That’s talent.
Why the village ensemble mattered
Most historical dramas (sageuks) get bogged down in the palace. The king yells. The ministers plot. We get it.
💡 You might also like: Wrong Address: Why This Nigerian Drama Is Still Sparking Conversations
But the cast of 100 Days My Prince excelled because of the Songjoo Village crew.
- Lee Joon-hyuk as the local official.
- Kim Ki-doo as Gudol.
- Lee Min-ji as Kkeut-nyeo.
These actors provided the "breathing room." Their comedic timing was the glue. When Won-deuk was being an arrogant jerk, they were there to humble him. They represented the heart of the show. Without them, it would have just been another political thriller. Instead, it felt like a community.
Actually, the cast became so close that they famously fulfilled a "ratings promise" by filming a dance video to EXO’s "Growl" in full costume. You can still find it on YouTube. Seeing a terrifying minister and a stoic prince doing K-pop choreography is exactly the kind of chaotic energy that made this cast special.
The technical mastery behind the performances
Let’s get nerdy for a second. Acting in a sageuk is hard. You have to use sa-geuk-to (a specific formal tone of speech). If you’re too modern, you ruin the immersion. If you’re too stiff, you’re a boring statue.
D.O. nailed the transition between the high-born dialect and the slightly more relaxed (but still weirdly formal) speech of Won-deuk. This wasn't accidental. It was a choice.
Director Lee Jong-jae (who later worked on Psychopath Diary) leaned into the cast’s strengths. He allowed for silence. In the scene where Won-deuk realizes his true identity, the camera stays on D.O.’s face for what feels like an eternity. No music. No flashing lights. Just an actor processing a shattered reality.
📖 Related: Who was the voice of Yoda? The real story behind the Jedi Master
Fact-checking the impact
When the show aired, it hit a peak rating of 14.4%. For a cable show in 2018, that was astronomical. It wasn't just a "fan-service" drama for EXO-Ls. It won over the general public in Korea, which is much harder to do.
The "Cast of 100 Days My Prince" became a blueprint for how to balance idol-actors with veteran theater actors. It proved that if you cast for chemistry rather than just "big names," the audience will follow.
What to watch next if you miss this crew
If you’ve finished the series and have a void in your soul, you don't have to look far. The cast has been busy.
- Do Kyung-soo: Check out Bad Prosecutor. It’s modern, but he keeps that same "uncomfortable" intensity.
- Nam Ji-hyun: You absolutely have to see Little Women (2022). She plays a reporter struggling with alcoholism and a massive conspiracy. It shows her range beyond the "plucky heroine" role.
- Kim Seon-ho: Hometown Cha-Cha-Cha is the obvious choice, but The Childe shows his darker, more violent side if you want something different.
- Han So-hee: Nevertheless or Gyeongseong Creature. She’s become a global icon for a reason.
The Actionable Takeaway
If you are a writer or a creator, look at how this cast was structured. It wasn't top-heavy. Every character, from the guy selling fans in the market to the King himself, had a motivation.
When you rewatch, pay attention to the "reaction shots." The genius of this cast is often found in the background. Look at Gudol’s face when Won-deuk says something stupid. Look at the Crown Princess’s eyes when she’s alone. That is where the real storytelling happens.
Stream it on Netflix or Viki, but do yourself a favor: watch it for the acting choices, not just the plot. You’ll see why these names are still headlining the biggest shows in the world today.