Lionel, raised in a violent and suffocating home, finds his first real affection when he meets Arthur, an immortal merman living in human form within an old castle. But Lionel's family is obsessed with a legend that promises eternal life through the body of a merman, and they set their sights on Arthur. Torn between love and the chains of his family, Lionel must decide whom he will protect. (Source: Lezhin Entertainment)