Sweet, awkward 16-year-old Ruby Gillman (Lana Condor, To All the Boys I’ve Loved Before franchise) is desperate to fit in at Oceanside High, but she mostly just feels invisible. She's math-tutoring her skater-boy crush (Jaboukie Young-White, Ralph Breaks the Internet), who only seems to admire her for her fractals, and she's prevented from hanging out with the cool kids at the beach because her over-protective supermom (Oscar® nominee Toni Collette, Knives Out), has forbade Ruby from ever getting in the water. But when she breaks her mom's #1 rule, Ruby will discover that she is a direct descendant of the warrior Kraken queens and is destined to inherit the throne from her commanding grandmother (Academy Award® winner Jane Fonda), the Warrior Queen of the Seven Seas. The Kraken are sworn to protect the oceans of the world against the vain, power-hungry mermaids who have been battling with the Kraken for eons. There's one major, and immediate, problem with that: The school's beautiful, popular new girl, Chelsea (Emmy winner Annie Murphy, Schitt's Creek) just happens to be a mermaid. Ruby will ultimately need to embrace who she is and go big to protect those she loves most.