Former mercenary Chloe’s biological daughter Mia, blessed with inhuman super strength, becomes the target of a sinister conglomerate. Mother and daughter defeat the evil group and rescue two orphaned superpowered twins, Leo and Lily. Three years later, the four lead a low-key life in Blackthorn City. Malicious colleagues and her greedy ex-husband constantly harass Chloe, but the three kids always stand up to shield their mom and defeat those villains. The leader of the evil conglomerate that once captured them returns, piloting a colossal mech to level the whole city. To save their city, the mother and her three children stop concealing their abilities and team up to destroy the giant machine.
