It’s Christmas! While preparing for Christmas Eve with family, Adrien is about to spend his first Christmas without his mother. Thinking that his father does not want to celebrate the holidays this year, the schoolboy, saddened, turns into Cat Noir and leaves the family home to sing his anger in snowy Paris.
When his father, Gabriel, discovers that Adrien is not in his room, he becomes worried, afraid that he could be in danger and anything can happen.
Hearing the news, Marinette immediately transforms into Ladybug, determined to find her Adrien.
When she finally finds him in the company of a Santa, Ladybug thinks the Santa is akumatized and wants to trouble Adrien.
Blinded by her love for the young man, Ladybug is wrong and creates negative emotions in Santa who actually becomes a victim of Hawk Moth. As a supervillain now, he is determined to make this Christmas the worst in the history of Paris.
Can Ladybug and Cat Noir succeed in saving Christmas?