Mermaid.. Korean light novel.. Long ago, I've read about a female MC who is a half human and half mermaid. It's a korean light novel and I've forgotten the title. The first chapter started sad and depressing, the MC's mermaid mother died because of the abuse from her human father who was an aristocrat. Before the mom died, she fed a pill to the young mc to make her a mute and avoid the same fate as her mother. She mustn't sing because she will die but her father abused her until she grew up. There's a scene where she is inside a cage, watched by nobles inside a hall as entertainment. Her father was the host. She couldn't take the abuse anymore and wanted to kill them all. So she sang. A mermaid's singing is somewhat like a drug.. an ecstasy for a human who hears it. She sang until all of them died but the consequence was that, she will die because of it. Before dying, the mature ML walked up to her and conversed with her. She died and then, she reincarnated into her young self. She somehow manipulated her father into selling her to ML's family (which was a feared existence). ML was still young and he doesn't have the memory of the last life. The last clue I remember is that the MC's name is Iris and ML is a noble.