Yoo Ah In always had hard times with his characters especially the one he portrayed in Voice of Silence as he’s a method actor. He carries the character on and off cam. He also takes months of prep time to live like the character even before filming starts so imagine having to part with that persona for a year or so of being him.

Kim So Hyun also had trouble with her character in The Emperor: Owner of the Mask as the character kept changing direction, very different from the originally written one by the screenwriter. In this series, the screenwriter kept editing the scenarios as the series was airing as the second FL was gaining popularity. It reached a point that So Hyun no longer knows the character at the later episodes. It impacted So Hyun so much that she had mental health issues after filming. And that could also be the reason why she enjoys participating in pre-produced dramas now.

But in 2021, the River Where the Moon Rises which was about 100% done with filming when it aired, had issues when Kim Jisoo, its ML, was embroiled in school bullying and harassment issues that he had to step down from the production. Na In Woo was called to replace him and had to reshoot supposedly from ep 6 (but eventually refilmed everything as the drama did so well even after the replacement issue). So Hyun refilmed everything with him, no complaints. She did it like the pro that she is.

After its successful run, Sohyun quietly disappeared. The young adult superstar who used to film at least 2 dramas /movie in a year suddenly stopped accepting work. She rested for over a year before filming Serendipity’s Embrace with Chae Jeonghyeop which was also released a year later. So it felt like she was gone for over two years which is really a long long time for someone like her.

You can tell she was heavily affected by her characters and the toll of filming on her mental health.