Following his breakout in hit drama My Royal Nemesis, rising actor Heo Nam-jun has officially locked in his next project: the period romance Whale Star: The Gyeongseong Mermaid on tvN. Early filming photos of the Heo Nam-jun Whale Star drama look, featuring long hair and period styling, are already sparking attention on social media.
The adaptation of the acclaimed Naver webtoon teams Heo with Choi Woo-shik and Moon Ga-young in a historical melodrama set in 1926 Gyeongseong, the name for Seoul under Japanese rule. For anyone searching the Heo Nam-jun Whale Star drama update, this casting confirms he is stepping into big-league territory and invites curiosity about how a tragic resistance fighter will reshape his image.
Heo Nam-jun Levels Up With Whale Star
Korean coverage has framed My Royal Nemesis as Heo Nam-jun’s breakout, and his next confirmed role makes that momentum feel very real. He is set to headline tvN’s period romance Whale Star alongside Choi Woo-shik and Moon Ga-young, putting his name on the same line as established K-drama heavyweights. The series follows young people caught in Korea’s independence movement in 1926.
Heo plays Song Hae-su, an independence activist who lost his family and now lives with unshakable conviction. A failed operation linked to an assassination attempt leaves him entangled with Heo Su-a, the maid played by Moon Ga-young, and Kang Ui-hyeon, Choi Woo-shik’s injured freedom fighter, binding the three in a chain of loyalty and guilt.
Directed by acclaimed filmmaker Hur Jin-ho, known for the film Christmas in August, and Yoo Beom-sang of Twinkling Watermelon and Study Group, the drama comes from TakeOne Studio and Studio Dragon. Filming began on April 24, 2026 in Gunsan, and tvN has slated the series for a 2027 broadcast that reimagines The Little Mermaid in a darker Korean independence setting with Heo’s character at its core.
Why This Webtoon Adaptation Feels Like a Glow-Up
The original Naver webtoon Whale Star: The Gyeongseong Mermaid ran from 2019 to 2021, earned a near perfect rating, and became one of the platform’s highest rated romance titles. It went on to win the Presidential Award in the comics category at the 2021 Korea Content Awards, giving the drama a built in audience and serious prestige. Reports of a long preparation period and careful casting process underline how high the stakes are, so placing Heo Nam-jun among the leads signals strong industry confidence in his future.
Long Hair, New Era for Heo Nam-jun
The glow up is already visible. KStarTrend, a K-drama trend account on X, posted on set photos and wrote, “Heo Nam Jun looks completely different with long hair as his next drama “Whale Star: The Gyeongseong Mermaid” filming photos spread online.” Just the longer hair and rugged styling make him almost unrecognizable to casual viewers.
For fans who met him through My Royal Nemesis, this shift into a grim, battle scarred independence fighter hints at a more intense and mature direction. Historical romances often become defining works for rising actors, and Song Hae-su’s mix of conviction, grief, and complicated love lines could showcase a wider emotional range.
As shooting continues, fans are waiting on official character stills, posters, and a first tvN teaser to see how Hae-su plays off Su-a and Ui-hyeon. International streaming plans are not yet confirmed, but Studio Dragon’s history with global hits has already put Whale Star on many watchlists, reinforcing Heo Nam-jun as one of the new names to watch in upcoming period romance K-dramas.