Usagi and friends goes to a vaction to Paris and meets a friendly bellringer Quasimodo and a lovely gypsy girl named Esmerelda and a face a new enemy called Judge Claude Frollo. (Alice and Pretty Cure 5 are the guest stars in the movie.)
In 1482 Paris, Clopin, a gypsy puppeteer, narrates the origin of the titular hunchback. A group of gypsies sneak illegally into Paris, but are ambushed by Judge Claude Frollo, the minister of justice, and his guards. A gypsy woman in the group attempts to flee with her deformed baby, but Frollo pursues and kills her outside Notre Dame. He tries to kill the baby as well, saying that it is an "unholy demon" from Hell, but is confronted by the cathedral's archdeacon, who accuses Frollo of murdering an innocent woman. To atone for his sin, Frollo agrees to raise the deformed child in Notre Dame as his son, naming him Quasimodo.
Twenty years later, Quasimodo develops into a kind yet isolated young man who dreams of seeing life outside the bell tower, but is told by Frollo that he is a monster and would be rejected by the outside world. A trio of living stone gargoyles: Hugo, Victor, and Laverne serve as Quasimodo's only company and friends. The gargoyles encourage Quasimodo to attend the annually-held Festival of Fools. He tries to go but is stopped by Frollo who says he should stay inside the bell tower. Outside Paris Usagi and friends arrive with Alice's uncle Phoebus and becomes friends with a gypsy girl named Esmeralda. While Phoebus meets up with Frollo, Usagi and friends decide to start their fun in Paris.
Usagi and friends celebrate the festival of fools and they get surprised to see Esmeralda dance and despite Frollo's advisories, Quasimodo attends the festival and he is celebrated for his bizarre appearance, only to be humiliated by the crowd after Frollo's men start a riot. Frollo refuses to help Quasimodo, but Esmeralda and her friends intervenes and frees the hunchback, and uses a magic trick to evade arrest. Frollo confronts Quasimodo and sends him back inside the cathedral.
Esmeralda and the others follows Quasimodo inside, but is followed by Captain Phoebus. Phoebus does not approve of Frollo's methods and refuses to arrest Esmeralda, his niece and her friends for alleged witchcraft inside Notre Dame and has them confined to the cathedral, Alice, Usagi and the others realised that Phoebus has fallen in love with Esmeralda. Esmeralda, encouraged by the Archdeacon, offers a prayer to God to help her and the outcasts. In the bell tower, Esmeralda and the others find and befriends with Quasimodo, who helps them escape Notre Dame out of gratitude for defending him. Esmerelda thanks Quasimodo with a pendant containing a map to the gypsies' hideout, the Court of Miracles. Frollo soon develops lustful feelings for Esmeralda and upon realizing them, Frollo begs the Virgin Mary (referring to her as Maria) to save him from her "spell" to avoid eternal damnation. After Frollo learns of Esmeralda and the sailor team's escape from the cathedral, he conducts a city-wide manhunt for them involving burning down numerous houses which he suspects would shelter gypsies in his way. Alice along with Esmeralda and the team spots her uncle Phoebus, who now realizing Frollo's evil reputation, defies him after being ordered to burn down the home of an innocent family and is sentenced to death, but flees. Phoebus is shot with an arrow and falls into a river, but Esmeralda and the others rescues him and takes him to Notre Dame for refuge. The gargoyles try to help Quasimodo feel better about himself, assuring him that Esmeralda would love him. Unfortunately, this is proven wrong as Esmeralda and Phoebus have fallen for one another, which Usagi and friends already knew.
Frollo returns to Notre Dame later that night and realizes that Quasimodo helped Esmeralda and the others to escape. He bluffs to Quasimodo saying that he knows about the Court of Miracles and that he intends to attack at dawn. Using the map Esmeralda gave to him, Quasimodo and Phoebus find the court to warn the gypsies and the sailor team. However, Frollo follows them and he captures all the gypsies present along with Sailor Moon and her team. Frollo prepares to burn Esmeralda at the stake after refusing his advances, but Quasimodo, chained up inside the Bell Tower, manages to break free and rescue her in time, bringing her to the cathedral. Phoebus then frees his niece and her friends and the gypsies and rallies the citizens of Paris against Frollo and his men, who attempt to break into the cathedral. Quasimodo and the gargoyles pour molten copper onto the streets to ensure no one enters, but Frollo successfully breaks in. He pursues Quasimodo and Esmeralda to the balcony where both he and Quasimodo fall over the edge. Sailor Moon and friends arrive to save them and Sailor Moon uses her rainbow spiral heart sceptre to defeat Frollo and he falls to his death in the molten copper, while Quasimodo is caught in time by Phoebus on a lower floor. Afterward, Quasimodo comes to accept that Phoebus and Esmeralda are in love, and he gives them his blessing and so did Usagi and friends. They then encourage him to leave the cathedral into the outside world, where the citizens hail him as a hero and accept him into society as the gargoyles proudly watch from above.