Protecting Him (Luka x Fem Reader) (MLB x KNY crossover)

Y/N is the eldest daughter of Kagaya and Amane Ubayashiki. She's the Ornament Hashira and also will be next in line to take over the Demon Slayer Corps and the Corps Box. The Corps Box is not the same as the Miracle Box with no Kwami's and so far only 15 Miraculous's. When someone becomes a demon slayer, they are given a ring that transforms into a sword when needed. A Hashira is given a Miraculous when becoming one and either turned into something they wear all the time, or kept as a ring. One day Y/N is assigned a mission to head to Paris along with demon slayers of her choosing. She's heard of superheroes Ladybug and Chat Noir that they have their own Miraculous Box, aka the Miracle Box. But they don't know about the demons yet or about Japan's Miraculous Box, so she must go undercover to secretly deal will the demons. Y/N luckily has glasses to know who's a civilian, demon, or even superhero and one day when on patrol, she finds someone getting attacked by a demon. She saves him and the next day when sneaking around, runs into him again. It's Luka Coffaine who quickly recognizes her. Y/N has no choice but to explain everything and the two quickly form a bond, Y/N even recruiting him and giving him another pair of glasses similar to hers. However, Y/N soon gets word that 12 Kizuki's have appeared in Paris and sends out for the Hashira's but can she protect Luka against an Uppermoon?

This is a Luka Coffaine x fem reader.
The characters aren't mine the MLB characters belong to Thomas Astruc and the KNY characters belong to Koyoharu Gotouge.
I also go by my AU, plot, and timelines in this crossover, so any mistakes, I'll take credit for.
When Y/N arrives, it's right after the Mugen Train where she saves Kyojuro and just in a random time in the MLB timeline.
Y/N means Your Name.
When I say my AU, there are some changes. For example, I have not seen the new MLB specials yet, only the episodes on Netflix so I'm only covering those.