Deep-sea mermaid Livia sacrificed her eyes as a child to save the three Ruggeri brothers, sealing a marriage pact in exchange. Adopted and raised on land for twelve years, she secretly loved the youngest brother, Santino—until, as the deadline approached, she caught the three brothers in an affair with the undercover agent Serena. Heartbroken, she tore up the pact herself and declared she would marry Aegir, the Deep-Sea King. Egged on by Serena, the brothers repeatedly harmed Livia—using her as bait, forcing her to shed tears of blood, cutting open her tail to extract the mermaid pearl. The curse for breaking the oath took effect: the brothers aged rapidly and were cast out of the family. After learning the truth, they knelt at Livia's wedding, begging forgiveness. Livia tore up the photo in public and refused to forgive. In the end, she was crowned Queen of the Deep Sea, standing beside Aegir—while the three brothers, having lost the girl who once gave everything for them, turned into a pile of bones.
