One fateful night, a group of traitors staged a coup, overthrowing King Triton and seizing the throne for themselves. With the Throne of Seal in their possession, they unleashed chaos upon the ocean, plunging it into darkness and despair.

In the midst of this turmoil, a young mermaid named Marina emerges as the kingdom's last hope. With the guidance of ancient sea spirits, she embarks on a perilous journey to reclaim the Throne of Seal and restore