Every year, a few actors suddenly capture drama viewers' attention with a surprising breakout role that sets them up for future stardom. Some of these actors have patiently played side characters until they hit the right role at the right time that really makes them shine, while others come out of the gate running, snatching attention in rookie performances. Here are 12 Korean actors who hit the jackpot with breakout roles in 2015:

1. Ji Soo

Breakout roles: Angry Mom and Cheer Up

2015 was a very, very good year for rookie actor and new Korean "It" guy Ji Soo. He grabbed hearts as the angry kid with an ahjumma crush in Angry Mom and then broke our hearts again as the troubled friend in Cheer Up. He's poised to start off the new year with a bang in his first starring role opposite Kim So Hyun in the 2-episode drama special Page Turner.

2. Park So Dam

Breakout roles: Because It's the First Time, The Priests, The Silenced

If Ji Soo is Korea's latest "It" guy, Park So Dam is the latest "It" girl. Drama fans might have missed her leading role in the charming cable series Because It's the First Time, but she had roles in a whopping five movies this year opposite some of Korea's biggest stars. While some of these roles were minor, her star is rising incredibly fast as she jumped from bit parts to the lead in the course of a year.

3. Park Bo Gum 

2014 put Park Bo Gum on people's radars, but I would say that 2015 cemented his trajectory to stardom. Not only is Answer me 1988 a huge hit right now, but Park Bo Gum also managed to show off his acting range with some very, very different projects. Keep slaying us with that wonderful smile!

4. Hyeri

Breakout roles: Detectives of Seonam Girls' High School, Answer Me 1988

If the Answer Me dramas are good at one thing, it's showcasing their female leads. Many netizens were vocally skeptical of Hyeri's ability to carry this series, but she should be grateful that the production team stood by their decision to cast her because it turned out to be the perfect project for her! This series will likely open doors to other projects, much like earlier Answer Me shows did for Eunji and Go Ara.

5. Ryu Joon Yul

Breakout role: Answer Me 1988

Yep, that's three in a row from Answer Me 1988, and I could keep going with the other cast members, but I'll stop here. Why is this drama such a big break for him? Well, he only started acting this year, for starters. He was so far off of people's radars that no one even considered that he might have a leading role in this series. Suddenly, he's holding his own in shipping wars against a very lovable Park Bo Gum in one of Korea's biggest rating hits of the year. Yeah, I'd say that's a good career move.

6. Yoo In Young

Breakout roles: MaskOh My Venus

Before this year, I definitely recognized Yoo In Young's face from various dramas, but her double whammy of evil-yet-oddly-likable second female leads this year leaves me wanting more as a viewer. Maybe it's her hilarious facial expressions, or maybe it's that soft vulnerability even when her characters are being totally evil. Whatever the case, she's immensely enjoyable to watch, and I'm hoping that a redemption arc in Oh My Venus will move her one step closer to a leading role instead of pigeonholing her as the second lead in increasingly high-profile dramas.

7. Choi Woo Shik

Breakout roles: Fool's Love, Set Me Free

Choi Woo Shik ended last year with a string of supporting roles in ensemble shows. This year, he finally landed his first leading role in the unique comedy Fool's Love. He also brought home several Best New Actor awards for the movie Set Me Free, which technically premiered at the end of 2014, but it was still making the film festival rounds early this year and it qualified for this year's film awards, so we'll count it!

8. Chae Soo Bin

Breakout roles: Bluebird's HouseCheer Up!

Chae Soo Bin was giving viewers emotional whiplash this year with her opposite roles in Bluebird's House and Cheer Up. In one, she was sweet and kind, and in the other, she was the antagonist everyone loved to hate. She just brought home a Best New Actress trophy from the APAN Star Awards, so I'm sure we'll see more of her soon!

9. Yook Sungjae

Breakout roles: School 2015, The Village: Achiara's Secret

How, exactly, does one go from being a rookie idol actor to suddenly sharing a screen with Moon Geun Young in the course of a year? The answer is simple: give everyone a crazy case of second lead syndrome in a little show called School 2015.

10. Jo Soo Hyang

Breakout role: School 2015

It was a good year for drama villains, and rookie actress Jo Soo Hyang held her own in the crowd, pulling in a Korean Drama Awards nomination for her role. With two movie roles and two TV specials under her belt this year in addition to School 2015, she's off to a great start.

11. Byun Yo Han

Breakout role: Six Flying Dragons

After the success of Misaeng at the end of 2014, all of the cast members were poised for success. While Byun Yo Han's first leading role in Ex-Girlfriend's Club didn't do well in ratings, his follow-up role as Joseon's best swordsman in Six Flying Dragons is showing off the actor's ruggedly sexy side. Take his recent spectacular swordfight as a perfect example. He still has another 30 episodes to go until the end of the series (unless, of course, his character dies much earlier), but I'm pretty confident he won't have to wait long for another drama offer.

12. Lee Yoo Bi

Breakout roles: Pinocchio (end of 2014-early 2015), TwentyScholar Who Walks the Night

Lee Yoo Bi was circling around leading roles for a while, but Pinocchio was the big break she needed to push her into the limelight. After costarring with Lee Joon Ki, what's next for the talented actress?

Which stars caught your attention this year? Which breakout roles were your favorites? Share your thoughts in the comments!

Watch the talented young cast of Answer Me 1988 below: