Facts behind Fantasy: Dissecting the Captivating World of Korean Dramas

DataRes at UCLA
12 min readMar 16, 2024

Mingyang Li (Project Lead), Hannie Xie, Michelle Sun, Ethan Lee


Are you a lover of heart-fluttering romances, tear-jerking melodramas, and jaw-dropping plot twists? Are you still lost in a sea of “to-watch” lists and endlessly scrolling through streaming platforms trying to decide which K-drama to binge-watch next? Well, do not worry, we got you! Read on as we unveil the facts behind fantasy by dissecting the captivating world of K-dramas. Korean dramas, fondly known as K-dramas, have an intriguing background deeply rooted in Korean culture and history. From the early days of iconic dramas like Boys Over Flowers to modern masterpieces such as Crash Landing on You, K-dramas have captured the hearts of millions around the globe.

As we analyze the 250 highest-rated K-dramas over the past two decades, it is not surprising to observe an increase in its popularity. The bar chart above shows a striking upward trajectory of the number of top-rated K-dramas over the years. It is not just a gentle incline; it is a heart-pounding ascent that mirrors the global frenzy for K-dramas. Indeed, with the emergence of the Hallyu Wave, this tidal wave of Korean culture has washed over shores far and wide, drawing folks from every corner of the globe.

Popular Genres

So, what are some of the most popular K-drama genres? From the word cloud, we can see that the 3 most popular genres are romance, drama, and mystery. These genres have become the bread and butter of K-dramas, captivating audiences with their irresistible charm and endless intrigue.

First up, let’s delve into romance — the genre that sets hearts aflutter and pulses racing. The age-old saga of enemies to lovers, where two fiery souls find themselves irresistibly drawn towards each other, never fails to captivate our hearts and minds. Similarly, star-crossed lovers navigating the highs and lows of forbidden love or the classic tale of love at first sight leave us longing for more.

But hold up, things take a drastic turn with epic family feuds or corporate struggles! The plot becomes more dramatic as age-old grudges, buried secrets, and deep-seated emotions threaten to tear families apart. Before you know it, alliances forged are broken and the line between friend and foe blurs into obscurity. From forbidden love affairs to bitter betrayals, these intricate plot twists keep us on the edge of our seats.

And who could forget mystery, where we embark on a thrilling adventure and immerse ourselves in the plot as detectives alongside our favorite characters, piecing together clues and unraveling truths? Whether it’s a shadowy conspiracy or a chilling murder mystery, one thing’s for sure — in the world of K-dramas, the allure of mystery is irresistible, drawing us into a world where nothing is as it seems and the truth lies hidden beneath the surface, waiting to be unveiled.

Genre Influence on Ratings

Many might believe that the most popular genres should contribute most to how highly a show is rated. After all, popular genres such as romance, drama, and mystery are popular for a reason, right? However, as our dive into the data reveals, popularity does not always parallel influence when it comes to K-drama ratings.

To unravel this, we created a radar chart that summarizes the dataset into a vivid illustration of genre influence. Instead of reflecting the number of highly rated shows in each genre, each genre’s ‘spoke’ represents the comparative average rating of each genre, derived from all the dramas listed within each genre. A “spoke” is akin to a compass needle, with each genre’s “spoke” extending outward to a degree that matches its average rating. Here’s where the plot thickens: the expected champions of the genre realm — the romances, melodrama and mystery — do not necessarily tower over the rest. Rather, we notice that less popular genres such as psychological and action have the longest spokes that reach farthest out in the chart. On the contrary, popular genres such as romance have much shorter spokes, giving credence to the fact that the best shows may lie in the more niche, “hidden gem” genres. Interesting!!!

Optimal Episode Length and Count

In addition to our preferred genres of shows, a question that often arises, particularly in the age of modern social media, is whether we are easily bored or constantly seeking more engaging content. To explore this, we conducted an analysis that examines three key variables simultaneously using a scatter plot: episode length, episode count, and the overall rating of the top-250 K-dramas.

The data reveals an intriguing trend: the majority of these highly rated K-dramas tend to cluster around a specific pattern. Typically, they consist of approximately 16 episodes, each lasting about an hour. However, the most highly acclaimed dramas appear to fall into two distinct categories: shorter episodes averaging 45 minutes with fewer episode counts of around 8, or longer episodes extending up to 1.5 hours, paired with a typical episode count of 16.

There are several potential explanations for this phenomenon. One possibility is the prevalence of shorter attention spans in today’s society, prompting a preference for concise episode lengths that hold viewers’ interest. Conversely, longer episodes may provide audiences with a deeper connection to the characters and narrative universe. No matter the episode lengths, it seems that viewers continue to have a profound appreciation for Korean dramas!

In summary, the data suggests that the optimal formula for a highly rated K-drama lies in striking a balance between episode length, episode count, and overall storytelling quality. This insight underscores the evolving preferences and viewing habits of audiences in the realm of contemporary entertainment.

Best Day to Air a K-Drama

Imagine you are a producer of an upcoming K-drama, currently trapped in a conundrum. Which day of the week should you be airing the drama to maximize audience popularity and ratings? Intuitively, it seems like weekends will be the obvious choice. Away from work and school, weekends are the ideal time for relaxation for many of us, often indulging in K-dramas for a much needed breather away from the hustles and bustles of reality. Hence, given the diverse audience base, weekend nights are considered the “prime time” to air K-dramas, as they are usually reserved for the hotly anticipated dramas starring fans’ most beloved A-list stars. We hypothesize that there will be a higher number of top-250 K-dramas aired on weekends than weekdays.

As expected, 94 of the top-250 K-dramas were aired on Saturday, 23 more than the second-highest. If you found this statistic predictable, brace yourself for the upcoming plot twist. The second-highest is neither Friday nor Sunday, but Wednesday with 71 dramas aired. Even more surprisingly, Friday and Sunday were the days with the fewest top-250 K-dramas aired, in fact fewer than all other weekdays. To fathom the root cause of this bewildering phenomenon, let us dive deeper into an in-depth analysis.

Instead of analyzing all top-250 K-dramas as a whole, we split them into 5 groups based on their audience rating rankings. The line plot above provides a much clearer explanation for the discrepancies observed earlier. Represented by the blue line, 62% of the top-50 dramas were aired between Friday to Sunday. These are the popular primetime dramas catered towards diverse audiences, such as Goblin and Crash Landing on You. Led by internationally renowned stars along with talented and experienced production teams, these dramas had already accumulated lots of hype before they were even aired, thus easily securing the weekend primetime airing slots. As long as they do not turn out too disappointing, fans will accord them high ratings, at times merely to show support for their favorite actors and actresses. Hence, the top-50 list is dominated by weekend primetime dramas.

On the contrary, most weekday K-dramas are targeted at niche audience sectors, with genres ranging from thriller to melodrama to romcom. Although not as widely popular, the quality of weekday dramas are no less inferior to the weekend ones. Flower of Evil is known for its spellbinding plot twists and cliffhangers, whereas Our Beloved Summer’s realistic and heartwarming portrayal of various forms of love — romantic, platonic and familial — hits right in the feels. Lamentably, with a more limited fanbase, weekday dramas are less likely to break into the top 50, with most ranking between 51 to 250. However, weekday dramas span across a plethora of genres, so there are more weekday dramas than weekend primetime dramas among the top 250. Hence, in the previous treemap, there are more top-250 K-dramas aired between Monday to Thursday than Friday and Sunday. Saturday has the highest number since most weekend dramas are aired consecutively on either Friday and Saturday, or Saturday and Sunday.

In addition, our previous hypothesis that there will be a higher number of top-250 K-dramas aired on weekends than weekdays was based on the fact that most audiences have more free time during weekends. Yet, this turned out to be invalid since the burgeoning of online streaming platforms like Viki and Viu has enabled viewers to watch these dramas whenever they desire. As a result, weekday dramas have gained increasing exposure and popularity among viewers who had insufficient free time over the weekdays to indulge in dramas. Therefore, the ratings for weekday dramas turned out to be higher than initially expected.

Korean Drama Recommender

After laying the groundwork through exploratory data analysis, the stage is now set for the climax — building a Korean drama recommender. When a user inputs his or her favorite K-drama, our recommender will adeptly propose 5 other top-250 K-dramas with similar characteristics that the user will most likely enjoy watching too.

First, we identified 4 key features to assess similarities between K-dramas: Number of Episodes, Genres, Tags, and Cast. Out of the entire cast, we only extracted the lead and key supporting actors and actresses since they serve as significant pull factors for many audiences, particularly among their dedicated fanbase. Features such as Year of Release and Day of the Week Aired On have been omitted because these dramas are not currently airing. Since audiences have the flexibility to watch them at their own convenience via online platforms, which day and year these dramas were aired hold less importance.

After selecting the 4 key features, we concatenated them into a single feature vector. However, most of the feature values are represented in words (Genres, Tags, and Cast), which Machine Learning models, such as our recommender, are unable to comprehend. Hence, we used the Term Frequency-Inverse Document Frequency Vectorizer to convert these words into numbers by calculating the weightage of each word in the feature vector. Now, each K-drama is represented as a numerical vector in a multi-dimensional feature space.

Following that, we utilized Cosine Similarity to determine the likeness between each pair of vectors, with each vector representing a specific K-drama. The image above provides a visual explanation of Cosine Similarity. Given two vectors, if their Cosine Similarity value is closer to 1, the angle between them is closer to 0 since cos(0) = 1. This indicates that the two vectors are extremely similar, and vice versa. Finally, based on these similarity scores, our recommender will suggest to the user the 5 top-250 K-dramas that are most similar to his or her favorite K-drama.

Now, let us put our Korean drama recommender to the test. Since its release, Hospital Playlist has captured the hearts of fans all over the world, rightfully earning its place as the third-highest rated K-drama. The authentic portrayal of the 5 lead characters by the talented ensemble cast and the highly relatable plot revolving around friendship and life are key contributing factors to its overwhelming success. For the ardent fans of Hospital Playlist looking to watch similar dramas, here are our recommender’s top picks.

To no one’s surprise, Season 2 of Hospital Playlist is ranked top (which proves the reliability of our recommender!). Age of Youth and Be Melodramatic are also dramas on friendship and life, whereas Dr Romantic is one of the most popular dramas depicted in a medical setting. Given all these recommendations that represent K-dramas that are most similar to each other, let us try to visualize the relationships between K-dramas based on their Cosine Similarity values.

Using our recommender, we constructed a directed graph network for the 100 highest rated K-dramas. Each node represents one of the top-100 dramas, while each directed edge denotes the relationship between each pair of dramas. The tail of a directed edge is the user-inputted favorite drama, whereas the corresponding head of the directed edge is the recommended drama.

Since the indegree of a node is the number of edges leading into that node, the higher the indegree of a node, the more similar that drama is to other dramas. The nodes with the highest indegrees are circled in red, led by Dr Romantic with an indegree of 7, while Mouse, Cruel City and Age of Youth have indegrees of 6. Therefore, these few K-dramas have the highest probability of being proposed to users by our recommender.

Furthermore, this digraph network provides an alternative way of assessing similarities between K-dramas via calculation of shortest paths. For instance, the shortest path between Flower of Evil and Sweet Home is of length 2, whereas the shortest path between the former and D.P. is of length 4. Thus, we can conclude that Flower of Evil is more similar to Sweet Home than D.P.


With the meteoric rise of the Hallyu Wave since the 2000s, the world of Korean dramas has evolved into a global phenomenon, captivating audiences with its diverse genres, compelling storytelling, and memorable characters. Through our analysis of the 250 highest-rated K-dramas from the past two decades, we uncovered a plethora of interesting trends regarding the tastes and preferences of viewers.

While romance, drama, and mystery emerged as the most popular genres, less popular ones such as psychological and action often outshine the expected champions in average ratings. This emphasizes the significance of exploring diverse genres to discover hidden gems that may not be as mainstream, yet offer exceptional quality. Furthermore, the optimal episode length and count for K-dramas appear to be 16 episodes, each lasting about an hour. However, outliers in shorter or longer formats indicate that viewers appreciate variety and are open to different storytelling structures. Last but not least, our analysis of the best day to air K-dramas challenged common assumptions. The dominance of weekend primetime dramas in the top-50 list contrasts with the broader range of genres and themes among weekday dramas, further showcasing the diversity within the K-drama landscape.

To enhance viewer experience, we designed a Korean Drama Recommender that utilizes key features such as number of episodes, genres, tags, and cast to propose similar dramas based on a user’s favorite drama. Hence, if you feel lost, or spoilt for choice, in the vast sea of K-dramas, fear not as our recommender will lead you in the right direction!

As the popularity of K-dramas continues to soar, fueled by the creative producers, talented actors, and dedicated production teams, the landscape remains dynamic and ever-evolving. Whether you’re a seasoned K-drama fan or a newcomer, the rich tapestry of storytelling in K-dramas offers something for everyone, making it a cultural phenomenon that transcends borders and connects people through the shared experience of compelling narratives and emotional journeys. So, grab your popcorn and brace yourself for the next heart-fluttering, tear-jerking, and jaw-dropping adventure in the world of K-dramas!