Marinette Dupain-Cheng is born when the Justice League is still young but has existed long enough to be trusted amongst most countries. While it is the „Justice League of America" they are working with the UN, so their influence is far greater.
Marinette grows up with stories about superheroes. So when she is older she wants to become one, too. There are already child-heroes, the first being Robin, Batman's Partner, and there was a big discussion that went over the two-year-old's head. She heard of it when she entered school, and she doesn't know why people complain, the young heroes are being trained for it, and they get to protect people. It only makes her want to be one even more.
When she is twelve she doesn't want to be a hero anymore. Rumors about the death of the second Robin are spreading, the discussion about child heroes is going strong again. Only when the first generation of Child heroes, especially Robin, who's been Nightwing for some time now says that „it's safer for them to be with their mentors because they would be out there, even if they would be out alone" do they end.
When Robin reappears there' s a noticeable difference between how he was before Batman was Solo again and now. Everyone thinks it' s another child taking up the mantle. Marinette prays for them to survive.
There's a new boy in her class. It's the Adrien Agreste, and if she didn't have a celebrity crush on him before, she is now crushing on him hard.
When Marinette turns Sixteen a new member of the Bat-clan, Red Robin, makes his first appearances and the first Supervillain, later dubbed „Stoneheart" attacks. She is scared and wants to hide. Alya does not.
She finds the Ladybug Miraculous and still wants to hide. She doesn't want to be a hero. Her best friend Alya would have been the better choice. She's done some self-defense training and is always informed about heroes. She probably knows how to hero. But her Kwami, Tikki won't allow it. So, for the first (and she hopes the last) time She says „Tikki, spots on!" and becomes Ladybug.
Tim is exhausted. The time-travel solution had him up all night… for a week straight. He feels sick, tired and satisfied enough to not be nearly as angry as he should be when Damian announces that Grayson would be taking him on patrol as Robin. He just nods, goes to his bed, and then he sleeps.
He got sick from overdoing it. It takes a month to be able to fight again, and another two weeks for Bruce to clear him for field-work. He can't be Robin again, he knows, and so he decides on Red Robin. He had always liked the color red.
Everything is back to normal a month later. And then Paris is attacked by a Super-villain. There are no Heroes in Paris, and Superman has been sent with the Flashes to get there as fast as possible. They had been unable to build Zeta-tubes to Paris and a lot of other European cities without heroes. When they arrive two new heroes have already defeated him. They want to talk, but they disappear quickly, Superman reports hearing a beeping sound coming from their ornaments, a black ring for the later named „Chat Noir" and „Ladybug's" red earrings.
They try to contact the heroes, but they always disappear right after they „de-evilize" the Akuma. They express their interest in meeting, but the hero team doesn't respond. Batman suspects that they might not talk to another very much outside of their fights.
A month after their debut Batman tells Red Robin to investigate the Parisian heroes. His civilian cover will be that of an exchange student. Tim doesn't mind, Paris has a lot of things to draw. Red Robin is meant to make contact with the heroes and invite them to a talk with the Justice League. Batman tells him to find out their civilian identities. Tim is good at that.