Xiangyang is a merman raised by humans. He was born with both male and female characteristics, making him different from others, and he often feels lonely. Legend has it that merfolk can control all schools of fish and heal all injuries. There is also a rumor that they only determine their gender after finding true love, and from then on, they remain with their partner for life. One day, he discovered information about his tribe on Lu Jiajia's blood pearl. To return home, he deliberately drew near her, but gradually became captivated by her and fixed his gender for her. From then on, they used their love to protect this green sea and their shared homeland...
