Every great musical rivalry has people pulling the strings behind the scenes — and tvN’s upcoming drama just revealed exactly who’s shaping its young pianists’ futures.
“Four Hands, Two Sonatas” follows Kang Pio (Song Kang) and Choi Jeong Yo (Lee Jun Young), two pianists whose friendship, rivalry, and growth unfold from their arts-school adolescence into professional adulthood. The title borrows from the piano duet tradition of two performers sharing a single instrument — a fitting metaphor for a story built on parallel musical journeys. Alongside Song Kang and Lee Jun Young, Jang Gyuri rounds out the young cast as violist Hong Jae In.
Four Hands, Two Sonatas: The Adults Shaping Their Musical Fate
The drama’s newly revealed supporting cast — Jung Jin Young, Yoon Sea, Kim Joo Hun, and Seo Jae Hee — each play figures whose influence will steer the three young musicians’ paths in very different directions.
Jung Jin Young takes on the role of Kang Seung Woon, Kang Pio’s grandfather and a globally renowned conductor. A perfectionist who has stayed at the top of classical music for decades, he accepts nothing short of excellence — even from his own family — instilling in his grandson a deep hunger for his approval.
Yoon Sea plays Kang Ji Hye, Kang Pio’s mother and Kang Seung Woon’s daughter. Having recognized her son’s talent early, she’s poured herself into supporting his career — but Choi Jeong Yo’s arrival stirs new anxiety in her, setting up tension that’s likely to fuel the central rivalry.
Kim Joo Hun plays Do Hyun Soo, the teacher guiding both young pianists. Trained in Korea and seasoned by a career in the United States, he works to draw out the strengths of two students who are near-opposites in temperament and style, building a mentor dynamic set against their fierce competition.
Seo Jae Hee rounds out the cast as Yoon Sun Joo, Kang Ji Hye’s stepmother and Kang Seung Woon’s wife. A violin major with real institutional power — she directs the Korea Group Cultural Foundation and chairs the board at the Korean Arts High School — she extends generous support to Choi Jeong Yo while quietly pursuing her own ambitions, leaving her true motives deliberately unclear. For more K-drama character breakdowns and premiere previews, check out our Korean entertainment coverage on TechnoSports.
Who’s Who
| Actor | Character | Role in the Story |
|---|---|---|
| Song Kang | Kang Pio | Pianist, lead rivalry |
| Lee Jun Young | Choi Jeong Yo | Pianist, lead rivalry |
| Jang Gyuri | Hong Jae In | Violist |
| Jung Jin Young | Kang Seung Woon | Grandfather, conductor |
| Yoon Sea | Kang Ji Hye | Mother, driving ambition |
| Kim Joo Hun | Do Hyun Soo | Mentor, teacher |
| Seo Jae Hee | Yoon Sun Joo | Stepmother, hidden agenda |
Why This Cast Matters
What makes “Four Hands, Two Sonatas” compelling isn’t just the central rivalry between two gifted pianists — it’s the web of family pressure, mentorship, and quiet manipulation surrounding them. A demanding grandfather, an anxious mother, a grounding teacher, and a stepmother with unclear intentions each pull the young musicians in different directions, layering personal stakes onto every performance. It’s a setup that promises more than a simple talent competition — it’s a story about who gets to define success, and at what cost. For more drama previews as premiere dates approach, follow our culture and entertainment updates on TechnoSports.
“Four Hands, Two Sonatas” premieres August 29 at 9:10 p.m. KST on tvN.
