The sacred fan, passed down through generations of Uchiha clan leaders, ended up in another world after the Fourth Great Ninja War. By chance, it took human form and was taken in by the Edogawa couple. It even got an older brother named Edogawa Ranpo.
When the fan spirit, named Uchiha Kaeshi, started middle school, his older brother Ranpo casually sent him to Hyotei. As for why...
"Obviously because Hyotei's tennis team is pretty good! And remember to bring back some of the school's special snacks!" said his famous detective brother.
The fan spirit declared, "My big brother really does think of me first!"
The Detective Agency crew: "The second half is the real reason, isn't it?! Blindly adoring your big brother is a bad idea!"
And so, a new member joined Hyotei's tennis club. Uchiha Kaeshi couldn't control his instinct to blow things away because he was a fan, so he hit away every ball he saw on the court. As a result, Hyotei's captain, Atobe, took notice of him.
"Your defense isn't bad. You even managed to return my shots. Pretty flashy, too. Is it because of your eyesight?"
The fan spirit replied, "It's just the Uchiha Rebound instinct. My eyesight is terrible."
When he reached the courts, the black eyes of Uchiha Kaeshi would reveal the shape of tomoe. No matter what move his opponent made, he could see right through it, then use his instinct to rebound the ball and counterattack. He became the player every tennis competitor least wanted to face.
His opponents: "Liar! Saying your eyesight is bad was definitely a smokescreen! Don't think you can do whatever you want just because you're a handsome Uchiha!"
The fan spirit: Who would've thought you could activate the Sharingan while playing tennis?
Theme: A good craftsman needs good tools
