Adrien Agreste is 27 years old, still working as a model for his father but living on his own. He has abandoned most of his high school friends, mostly due mourning over the disappearance of Ladybug. One night after he receives a box containing all the miraculous minus the butterfly and peacock, he finds his father's assistant dead, and is accused of the crime. Drawing upon the power of the Ladybug and Black Cat, he is sent back in time to the second semester of his junior year, two months before Ladybug's disappearance and his classmate Marinette's death.

Figuring that his classmate's death, or Ladybug's disappearance may have something to do with Nathalie's death, Adrien tries to get closer as friends to Marinette and get closer to Ladybug. Nino suggests entering the film completion again this year and everyone is willing to participate, and Adrien suggests for Marinette to play opposite to his lead, to help be better friends with her. The movie gets accepted and premieres at the contest, with Adrien taking Marinette as his date. He walks her home that night, then transforms into Chat Noir to keep an eye on Marinette. He instead finds out she is actually ladybug when she transforms on her balcony and goes out for patrol. He follows and catches up to her, but the attacked by Hawkmoth directly. Hawkmoth succeeds in killing Ladybug, but Chat takes her earrings and runs. He returns the jewelry to Master Fu before returning to the future.

Older Adrien runs to Alya and Nino's place, who tells them what he knows about Marinette and Ladybug. Alya and Nino leave for work, Adrien watching their kids when someone sets fire to their house. Adrien saves the kids, but runs with the kids once he finds the cops on site. He calls Nino to tell him what happened, and while Nino is thankful, he tells Adrien they need to fix this. Adrien and Nino meet for Adrien to give him back his kids, but Nino was tailed by the police so they capture Adrien. Adrien wishes to go back, promising to find a way to for sure save Marinette.

Adrien finds himself going back to the day Nino proposed the film, which Adrien again votes Marinette to be the lead. Adrien goes to Master Fu and tells him what he knows, to which Master Fu agrees they will need more heroes. Master Fu brings in Marinette who tells her they will be getting more heroes to help them soon. While on patrol one evening, Chat warns Ladybug that their friend Marinette is in danger, and he wants to do everything he can to save her. The film shoot goes well as does the competition. When Adrien walks Marinette home, he asks her if she can come with him. She agrees and he takes her to Master Fu, who agrees for Marinette to stay there for the time being. Adrien recruits Alya and Chloe (Who received a major humbling during film production) to help protect Marinette with the fox and bee miraculous. While on patrol with the new heroes, Chat is confronted by Hawkmoth. Chat calls for backup and the girls (including Ladybug) come to his aid before he falls unconscious into the river.

Adrien wakes up in a hospital, 22 years old and was in a coma for the past six years. He finds out they took Hawkmoth's brooch, but the man escaped. Alya and Nino are getting married, and Chloe is perusing a masters in political science. Gabriel had taken Marinette under his wing after thanking her for finding his son. Adrien is going through physical therapy while taking some online courses to help him catch up academically, with his friends' help. One day he remembers who Hawkmoth is as Hawkmoth confronts him, Marinette saves Adrien's life and Hawkmoth is sent to prison. A few years into the future and Adrien is attending college for physics, and is dating Marinette.

I didn't like how Kayo ended up with Hiromi in the actual show.

Whose Who:

Satoru - Adrien

Kayo - Marinette

Sachiko - Nathalie

Satoru's friends - Alya, Nino, Chloe