Seo Kang-jun Seemed Like a Perfect Student: Until Ahn Eun-jin Got Closer

Seo Kang-jun thought Ahn Eun-jin was the picture of poise when they first met. He was wrong, and she was quick to confirm it.

The two actors, who star together in the new KBS 2TV weekend miniseries Nobody But You, appeared in a video uploaded to the Harper's BAZAAR Korea YouTube channel on the 8th. The segment's premise was a playful compatibility test between co-stars, but it turned into something more entertaining: a mutual roast of each other's first impressions.

What they actually thought

Seo described his initial read of Ahn as "neat, graceful, and pretty", someone who projected quiet composure. The reality, as he quickly found out, is almost the opposite. "She's genuinely bright and extroverted," he said. "Full of energy and playfulness." Ahn laughed and offered her own nickname as evidence: Ahn Heung-jin, a play on her name that roughly translates to "Ahn Full-of-Energy." It's a nickname that, she implied, her friends invented for good reason.

Ahn's memory of their first meeting was equally specific. She remembered Seo arriving early, sitting perfectly still, and moving with what she described as textbook posture. "He was the archetypal model student," she said. The image stuck, until it didn't. Getting to know him better, she discovered what she called "a uniqueness that lives inside all that uprightness." She used the Korean concept of 4-chawon (literally "fourth-dimensional") to describe it: a slightly otherworldly, unexpected quality that surfaces once someone lets their guard down. It's not a criticism so much as a compliment, the kind of detail that makes a co-star genuinely interesting to work with.

The easy back-and-forth between them throughout the video made clear that whatever awkwardness existed in those early meetings is long gone. Their chemistry reads as the relaxed, low-stakes kind that tends to translate well on screen.

The drama they're promoting

Nobody But You premieres on KBS 2TV on the 12th at 9:20 p.m. KST. The Saturday-Sunday miniseries marks a new collaboration for both actors, who have individually built strong track records in the romance genre. If the Harper's BAZAAR clip is any indication, the natural rapport they've developed off camera should give the show a solid foundation to work from.