(I don't ship them romantically since it's a discomfort to me but this is a Brotp headcanon)

Shuichi stayed up all night one time trying to solve a case and didn't wake up in the morning.

Kaede learned about this so to wake him up, she played loud obnoxious piano noises which sure did make him jump out of his chair.

I headcanon them as twins so Shuichi would have to deal with this.

Sometimes Kaede would rant about how cute or hot her crush it (depending on who I ship) and Shuichi would listen, knowing full well that he couldn't even talk about his own crush without him turning red.

Bubbly older twin, emo younger twin.

(Brotp! Brotp!)