Oni, greatest actor of POT
There are a few guys in POT known for their trickery and acting skills, but the true master of acting is Oni. Despite being the #1 player in his first year, he's managed to trick most of the U17 camp into thinking he's just some guy on court 5. Even the guys in the know obviously have no idea how good he is minus Byodouin and a handful of the top 10. Unlike the usual acting stuff, he not only fools his opponents but he also fools the reader. For example we're led to believe Nakagauchi was someone who could've played Oni straight up (yeah right), or that Kintarou sitting the net on fire is supposed to be pretty impressive, even though it'd later turn out that setting the net on fire is pretty much nothing compared to Kishin aura. Unlike most actors, Oni goes all the way to get his act to work, as he's completely willing to purposely lose games to keep the act going. After all, if he played anywhere remotely like his full power you'd never have anyone besides Byodouin that would challenge him. And even if he's playing just enough to win, there's no way he can keep this act going for 3 years if he always happened to win every game he plays against the normal guys of U17 camp.
I'm still betting at some point we'll see Tanegashima owned and then Oni will be like 'yeah his technique is weak' and then people will ask but isn't that the only guy he didn't beat and Oni will be like, "I never said that was over tennis."