Princess Naia of Aquariel is a spirited mermaid who dreams of the surface world. Her life underwater is idyllic, but its beauty feels stifling as she craves something different. Stories of humans have always fascinated her, though her father, King Thalassor, forbids her from venturing beyond their waters. Despite her father's warnings, Naia frequently swims near the surface, captivated by the lights of distant ships and the music drifting across the waves.
In Nigeria, Prince Adewale prepares for his coronation. As the heir to a vast kingdom, his life is full of privilege, but his heart is heavy with the weight of responsibility. Adewale yearns for freedom from courtly obligations, even as his mother and advisors pressure him to solidify alliances through marriage to Princess Zainab, a union that would strengthen the kingdom's political ties.
One fateful night, Adewale embarks on a voyage to a neighboring kingdom. A fierce storm erupts, its unnatural fury orchestrated by the sea sorceress Iyami, who thrives on chaos between the two realms. Naia, sensing the storm's danger, defies her father's orders and rescues Adewale from his sinking ship. She carries him to shore, mesmerized by his strength and vulnerability.
As she gazes at the unconscious prince, Naia feels an unexplainable connection but knows she must leave before he wakes. Adewale awakens on the beach, recalling fragments of a luminous figure with a tail. Her image haunts him, and he vows to find her.