Yo-You cant be?! Makoto x legend reader

You, (Y/N) a simple girl who love water and swimming.
But your not normal, you have a gift. You can say that your the legendary"Dark-Mermaid". One of the best swimmer in Japan, a myth. But your real, its just that you have tell no one beside your best purple haired friend. Her name Safira's, a super model and singer.. Return to the story, you have change school to attempt Kou school's. That's another of your good friends but Safira was your first one.
You happen to enter the school to see some people deseparaly trying to have people for there club. It happen that you see Kou watching and you go to her saying:"Hey, hi Kou! I'm entering the school today! And what is this?", you said curious of what the boys are doing. When she turned around and saw you, her eyes lighten up and she hug you, saying:" (YY/NN)!! You're here now? Cool! Hihihi, oh and them..they try to recrute some people for the swim club. Because they want to re-open the club, only need one."
Thats how you're story start!