Kagami drags Marinette to Tokyo to help the Stellars defeat a new supervillain, but Marinette soon realizes her friend has another, untold reason for this trip to Japan.

To save the future from a terrible fate, Marinette becomes Chronobug and teams up with Bunnyx to defeat a mysterious opponent who travels through time.

Marinette's class is headed to New York, the city of superheroes, for French-American Friendship Week.

Miraculous holders from another world appear in Paris. They come from a parallel universe where everything is reversed: the holders of the Ladybug and Black Cat Miraculouses, Shadybug and Claw Noir, are villains, while the holder of the Butterfly Miraculous, Betterfly, is a superhero.