The Substitute

Big changes happen when Kataoka asks his old student to substitute for him for the summer....*warning: slow start, it will get better in future chapters, I hope*

Disclaimer: I have not seen the entire anime or read the manga yet, so I apologize for offending anyone for getting canon details I put in to this wrong. I am new to the fandom.
I do not own the Ace of diamond characters, locations or narrative, I just own my two characters. All credit goes to the author of the manga and creators of the anime.