Ad-lib-ui Sin

Thirty-year-old unemployed man Lee Tae-Gyu. From some point onward, he's been living a lifeless existence, unable to feel the full range of emotions. Struggling to escape his meaningless routine, he encounters a mysterious old man who grants him the ability to copy others emotions through a will-o'-the-wisp. While testing this power, he becomes entangled with drama writer Kwak In-Ho. This encounter sends Tae-Gyu's life spiraling in an unexpected direction. Thus, he finds himself standing at the threshold of a new path: becoming an actor.
(Source: Naver, translated)