Song Kang, Lee Jun-young, Jang Gyuri Face Tension in tvN's 'Four Hands, Two Sonatas'

The three longtime friends at the center of tvN's "Four Hands, Two Sonatas" are heading into their first real rift. Episode 9, airing Friday at 9:10 p.m. KST, turns a rehearsal room into the setting where their bond begins to crack.

In the new episode, conductor Choi Jeong-yo, played by Lee Jun-young, strongly criticizes the playing of pianist Kang Bi-o, played by Song Kang. Their manager Hong Jae-in, played by Jang Gyuri, watches the exchange with visible unease.

The three characters have known each other since their school days and are still close at age 27. Kang Bi-o served as the pianist for Choi Jeong-yo's conducting debut, staged after a nine-year absence. Choi Jeong-yo, in turn, helped Kang Bi-o return to the stage after a long slump. Hong Jae-in has stood behind their partnership from the start.

That balance shifts as they prepare a new joint performance. Choi Jeong-yo holds Kang Bi-o's playing to a stricter standard than before and keeps pointing out flaws, and the tension between the two continues to grow.

Stills released ahead of the episode show the three in rehearsal. Choi Jeong-yo stares at Kang Bi-o with a hard expression. Kang Bi-o looks uncomfortable in return. Hong Jae-in, who has supported the collaboration until now, watches the session with a tense expression of her own.

The reason behind Choi Jeong-yo's sharper critiques, and where it leaves the three friends, will play out in the broadcast.

Episode 9 of "Four Hands, Two Sonatas" airs at 9:10 p.m. KST.