In Paris, 1891, Mr. Agreste is the newest and most eligible bachelor in town for the Season, catching the eyes of dozens of heartstruck ladies, though it is only one who truly manages to capture his attention and she is not among those in the elegant ballrooms (or so he believes), but beside him on the rooftops of the City of Lights masked and ready for action. Even when an arranged marriage is meant to tie him to the delicate Ms. Marinette Dupain-Cheng, his heart can't help but ache for his lady of the night, his one true love, his Ladybug.