Puns
Hikaru "Davide" Amane may have been written off as a joker in middle school, but his true talent lies in every turn of phrase, every clever bit of wordplay.
It is his competency with correspondence that leads him to success in the legal field.
When he delivers his first subpoena as a young lawyer, he says the words he'd been waiting years for the perfect moment to say, "You've been served."
None of the people standing around him play tennis, so no one gets the joke.