So Ji-sub’s Mr. Kim Surges Past 20 Percent as Seo Su-min Draws Breakout Attention

SBS’s new Friday-Saturday drama Mr. Kim is turning into one of the fastest-rising Korean TV stories of the summer. Led by So Ji-sub, the revenge action series crossed the 20 percent mark in nationwide ratings with only its fourth episode, while rookie actress Seo Su-min is drawing separate attention for her role as the daughter at the center of the plot.

According to Kyunghyang Shinmun, Nielsen Korea counted the July 4 broadcast at 21.6 percent nationwide. That puts Mr. Kim behind only The Penthouse 2 and The Fiery Priest among SBS Friday-Saturday dramas by nationwide ratings, making the early climb especially striking for a series that premiered on June 26.

A fast climb for SBS

The drama did not start quietly. Its first episode opened at 9.5 percent, then rose to 15.7 percent for episode two and 18.8 percent for episode three. By episode four, it had crossed 20 percent and set a new personal best for the fourth consecutive broadcast. For a primetime drama market where many series build slowly or rely on streaming buzz, that week-to-week acceleration is the headline.

The fourth episode also gave viewers the kind of high-stakes sequence the show has been selling from the beginning. So Ji-sub’s Kim Bu-jang teams up with Sung Han-soo, played by Choi Dae-hoon, and Park Jin-cheol, played by Yoon Kyung-ho, as he searches for evidence connected to his missing daughter Kim Min-ji. Kyunghyang reported that the episode followed the wounded father pushing toward Myeongpo Port after being shot, keeping the drama’s action-driven premise at the center of the ratings surge.

The series follows a former special agent who has been living as an ordinary father until his only daughter disappears. That setup gives the drama a direct emotional hook: family desperation, action spectacle, and the image of a quiet parent forced back into a dangerous past. Its quick rise suggests that SBS has found a formula that is connecting with both traditional broadcast viewers and streaming audiences.

The drama is also available on Netflix, where Kyunghyang reported it reached No. 3 on the platform’s global non-English shows chart within three days of release. That streaming placement matters because it turns a domestic ratings story into a broader visibility story. Strong local ratings can create momentum at home, while Netflix exposure helps international viewers discover the series before the Korean broadcast run is even far along.

Seo Su-min becomes a second story

Alongside So Ji-sub’s star power, viewers have become curious about Seo Su-min, who plays Kim Min-ji. TV Report and SPOTV News both noted that Mr. Kim marks Seo’s formal acting debut. Her character is described as a daughter who has suffered school violence and is later abducted, becoming the reason Kim Bu-jang returns to the kind of life he had tried to leave behind.

Reports have also resurfaced Seo’s pre-debut online visibility. TV Report said the 2007-born newcomer previously uploaded a 43-second everyday video titled around taking off glasses and becoming comfortable with the camera. The clip, filmed casually on a bus, passed 3.28 million views as of July 1, while her personal channel reportedly gathered more than 140,000 subscribers despite having only two uploaded videos.

That background has made Seo’s casting feel less like a sudden introduction and more like the next step for someone who had already attracted public curiosity. SPOTV News reported that she had appeared in beauty content, discussed learning acting, and received interest from major entertainment agencies before choosing to pursue acting rather than singing or dancing. She is now under Y-One Entertainment.

For Mr. Kim, the timing is useful. A drama built around a father’s search for his daughter needs the daughter character to register with viewers quickly, even if the plot often places her in danger or absence. The public interest in Seo gives the emotional core of the story an additional real-world talking point, particularly as audiences look up who she is and where they may have seen her before.

What the early success means

The next question is whether Mr. Kim can hold or expand its audience after such a sharp early rise. Passing 20 percent by episode four creates high expectations, but it also raises the pressure on the drama to keep its action beats, mystery, and family stakes moving without exhausting the premise too quickly.

For So Ji-sub, the ratings reinforce his continuing draw as a drama lead in a genre built around restraint, physicality, and emotional urgency. For Seo Su-min, the attention is a rare debut spotlight: she is entering the industry through a hit drama while viewers are already searching for her earlier online presence.

For SBS, the bigger win is that Mr. Kim is now a drama people are tracking in real time. Its numbers, Netflix ranking, and breakout supporting cast interest have turned it from a new revenge-action title into one of the clearest Korean drama momentum stories of the week.