On the stage production Unchain, Jae-ha, played by Park Sung-woong, embodies Walter, while Young-woo, played by Oh Seung-hoon, embodies Singer. The two begin with a tense dynamic: Young-woo arrives late and shows little interest in the work, which prompts Jae-ha to push him toward discipline and craft. As rehearsals unfold, Young-woo becomes increasingly drawn to Jae-ha’s relentless passion for his craft, and he starts to devote himself to the role—reading the books Jae-ha lends him and tagging along on outings to hunt for props. Jae-ha himself is renowned for his method acting, fully inhabiting his character to the point of letting that persona seep into his daily life. Hearing about this, Young-woo secretly adopts a similar approach, and, through this intense immersion, he grows to love Jae-ha.
Jae-ha’s girlfriend Hee-won, Yoon Seung-ah, begins to sense the deepening connection between the two actors as they spend more time together. The tension in the theater grows as Jae-ha becomes increasingly tense and conflicted, unsure about his feelings for Young-woo. A pivotal moment comes when Jae-ha accidentally hurts Young-woo during a rehearsal, and later, in the emptiness of the theater, the two share a kiss that Hee-won witnesses. The situation escalates when Jae-ha drags Young-woo into Hee-won’s storage shed, where Young-woo acknowledges his feelings for Jae-ha and they kiss again. The trio’s dynamics spill into real life as they drive to the beach, where Young-woo posts pictures of them on Instagram, triggering rumors about their relationship. Soon, Young-woo’s manager and Hee-won confront them about the truth of their bond.
The day of the press conference for Unchain, Young-woo reveals that he posted those photos on purpose to share their love with the world. He asks Jae-ha if he loves him, but Jae-ha remains silent; at the press conference, he downplays the romance, insisting they were only acting and urging people to stop prying into their private lives and focus on the play. Devastated, Young-woo visits Jae-ha’s house while Hee-won and Jae-ha sleep, and the next day, Hee-won discovers another presence in the house after Jae-ha leaves, accompanied by the broken pieces of one of her sculptures.
In the first performance, Young-woo arrives late, and during their scenes his lines reveal that he hurt Hee-won, enraging Jae-ha. He asks Jae-ha to kiss him, and whispers that the kiss was not in the script. In the final scene, Young-woo acts out his character’s suicide but chooses not to use the safety mechanism, hanging briefly before Jae-ha supports him through the moment. After Young-woo wakes, he tells Jae-ha that he is now the perfect Singer, while Jae-ha remains only a mediocre Walter. The couple’s love feels real, yet they recognize they can’t pursue a life together outside their roles. Young-woo leaves behind the prop finger in the studio, signaling the end of their potential relationship. Ultimately, Jae-ha leaves the theater with Hee-won, the only person willing to accept him and his flaws.