Anyone knows stories like Gorae Byul - The Gyeongseong Mermaid ?
Gorae Byul is such a great story.
Try the other works by the same author for the melancholic vibe - Andante in her hand is still being regularly updated. The author wrote another work This Magical Moment, which is available for free on the Webtoon website and is completed. It's a lot more chill than either Gorae Byul or Andante in her Hand but still has commentary about societal discrimination.
If you're after the Gyeongseong setting, Count Tachibana (recently got updated today) is an intriguing read. It's set in the Japanese colonisation of Korea as well, but the themes of war and resistance is more like a backdrop, and is not a motivating factor of the characters like in Gorae Byul.
If you're after a retelling of a famous story, like Gorae Byul is of the Little Mermaid, and if you're okay with a BL novel, try Yess & Yes. It's a retelling of A Christmas Carol, but set in a world with dungeons and hunters. The structure and plot is solid, and exploration of the miserly MC's personality and motivations are done really well.
Is chapter 25 missing ?