During the French Revolution, France lives under the rule of the cruel Hawkmoth who enslaves peasants and sometimes murders them. But his acts of cruelty are defeated by the brave Cat Noir. One of the peasants he tries to kill is an orphan boy named Adrien but Cat Noir rescues him and gives him his lucky ring earning the child's admiration.
Unknown to France, Cat Noir is really The wealthy Felix Agreste who lives happily with his lovely wife Bridgette and their baby daughter Marinette. Hawkmoth learns Felix's secret and confronts him in his home. The two fight which results with Bridgette getting killed after taking a hit for her husband. Hawkmoth who once lusted for Bridgette, blames Felix for her death so he arrests him and steals Marinette as his own child.
Years later...
Adrien now a handsome young man and a thief but only steals to survive, sneaks into the kitchen of Hawkmoth's house to steal some pasteries when he sees Hawkmoth's ward, Marinette now a beautiful young woman and falls in love with her. He introduces himself to her politely, though frightened by the strange young man she develops a crush on him. But Hawkmoth spots them and has the man arrested despite Marinette's protests.
In jail Adrien meets Felix and they recognize each other after seeing the ring on Adrien's finger, the two escape. Felix explains to Adrien who he is and trains him to be Cat Noir since he's older now. Adrien becomes the Cat Noir and leads the French Revolution while trying to woo Marinette who Felix is desperate to be reunited with.
Marinette is headstrong and spirited young woman who's sick of watching the peasants suffer and wants to help them. Also Hawkmoth begins to lust for her so he forbids her from being around other man especially young men. Wanting freedom and to help her people, she masquerades as Ladybug which Hawkmoth knows nothing of.