The general rule is first come, first served, and it's clear at a glance that the three teens are closer to the seats than you are. You'd have to run to beat them there, and while you might be able to make it work with the excuse of being a kid and a foreigner, you don't really feel like making a scene over something as petty as seating arrangements - at least not when there's other perfectly available seats.
"Over here," you say to Cordelia and Lu-sensei, heading towards the man sitting by himself.
Cordy glances at the guy, does a double-take, and then stares at you with an expression that clearly asks if you've gone nuts. You can't really blame her, as the man in question - who looks to be about twenty - is easily over six feet tall and has the heavily-muscled build of a serious, power-based fighter. He wears beaten-looking blue jeans, a brown leather jacket, and no shirt, and his dark blue hair, while generally short, has several long strands hanging messily over his face and down his neck. As if the man's thuggish appearance needed any more reinforcement, he has bandages wound about his forearms, and a long scar that runs across his face and the bridge of his nose.
"Hey there," you say, coming up to the man.
He glances at you. "Whatcha want, kid?"
"I was wondering, are these seats taken?" You gesture to the spots around the man.
The big guy looks at you a bit closer. "I know you," he says, pointing. "The Under Tens champ, right?"
"I am."
Suddenly, he claps you on the shoulder. Not hard enough to knock you over, though you do get a sense of the great strength in the man's arm - and the equally great control he exercises over it. "Hell of a show you put on there yesterday, kiddo, especially that whole turning into a giant bit. The old fogies that run this thing must be pulling their hair out trying to figure it out." He grins. "That makes you okay in my book."
"...thanks?"
"Go ahead and have a seat," he says, gesturing the the empty spots around him. "Name's Sakaki Shio, by the way."
You introduce yourself, though he probably remembers your name anyway, and then introduce Cordelia and Lu-sensei. Sakaki surprises you by nodding his head respectfully to your teacher.
"Master Lu," he says.
"Mister Sakaki," the old man replies, with a similar, slighter gesture.
Well, that was easier than you were expecting.