Gamyeongeuk

Lee Han, an unknown actor with crazy acting skills but never seen the light of day. He saves the lead actor Kang Tae-Yoon on a filming set where an accident occurred and dies in his place, but when he wakes up, he has become 'Cha Si-Han' with the beauty of the other world... "The ratings, the articles, the reactions, they're all the best. The drama that was on the verge of failure has come back to life, thanks to Si-Han." Si-Han, who suddenly gained attention in a drama where he appeared as a supporting role, is suddenly subdued by someone with great force on his way home. "Mr. Cha Si-Han. You know me, right?" His breathing stopped as his heart dropped. The man, Kang Tae-Yoon, was looking at him and smiling brightly.

(Source: Kakaopage, translated)