In this day and age most of the shinobi of old had perished and so did their knowledge of chakra, but one certain Uchiha lived.
Izuku Uchiha was the great great grandson of Sasuke Uchiha of the leaf village.
He was born quirkless in a world of quirks, he had no intention of being a hero, in fact he despised heroes and their corrupt society.
Izuku was bullied until the bullying caused him to unlock his Sharingan and he beat his bullies to a pulp.
Izuku instead of being a hero was sold by his mother to a Shinobi and became a freelance ninja/bodyguard and he loved his job.
Izuku was walking home from a job when he saw a girl being attacked and he stepped in and beat the hell out of the three attackers of the girl.
Izuku: Damn cowards... Are you alright miss?
Momo: I'm quite alright thanks, would you like to come to my house so my parents can thank you?
Izuku walked with her to her home and they walked into the house and Momo introduced Izuku to her parents.
Mr. Yaoyorozu: Thank you so much for saving my daughter, you have no idea how grateful I am.
Izuku: No problem, although since you are the Yaoyorozu family I was wondering if you had an opening for a bodyguard?
Mr. Yaoyorozu: You could be Momo's personal butler, is that acceptable?
Izuku nodded and shook hands with Mr Yaoyorozu and said "I will be here on Thursday."
Time skip to Thursday
Izuku arrived in his best attire and. Greeted the family and went to bed as it was late, his room was next to Momo's.
The next morning Momo asked Izuku to take her to school and Izuku agreed, they then walked outside and she saw no car.Momo: Izuku, how am I getting to school?
Izuku: Susanoo.
Then a giant green humanoid with wings made of chakra appeared with them inside and flew away.