Threadhopping with this character? Sure thing, unless it's denoted as private! A warning is appreciated!
Hugging this character?: Expect to get shoved. If circumstance allows for a hug, expect a very stiff Mr. Kaiba.
Giving this character a kiss? Why would you do this? He will be both embarrassed and angry! Good luck getting close to him to land one but you're welcome to try!
Badtouching: Say hello to his fist.
Lovers: I wouldn't mind plotting this, Kaiba is far too complicated so good luck wit that!
Punching this character (provided they can fight back): Expect a fight. A very painful fight.
Is there anything you do not want mentioned near this character?: Not really, GIVE IT TO ME!
Easiest way to get on his good side: Don't talk, just do everything he tells you to do.
Easiest Way To Get on his Bad Side: Beat him at a cardgame Act like a complete moron. Be loud. Pretty much anything and everything that doesn't constitute the above.
Can I Hack his Journal?: Good luck. He's a technology genius!
Can he Hack my Journal?: Yes he can and he probably will.
Fourth Wall Breakage: Why not. It's not like he'll believe you.
Can I shapeshift/bodyswap/etc?: This would be interesting~
Maim/Murder/Death: With good plot, I'm all right with this!