Note: This was written for the Zexal Flash Bingo challenge, for the prompt "squabble between friends".
Fuya stood at the door, clutching Yuma's birthday present like a talisman, and knocked. The door was opened immediately by a young woman. He jumped backwards. She must have been watching from the window for incoming guests, but her sudden appearance startled him. With her red-brown hair and piercing gaze, she reminded him entirely too much of his mother.
"I'm here for Yuma's birthday?" It came out an uncertain squeak.
The woman just sighed and said, "Come on into the madhouse."
She stepped aside and let him into the house, where he found she was not exaggerating. It wasn't just that someone had filled the formerly modest house with balloons, streamers, banners, and bits of miscellaneous decorating. It was that it was crammed with people, all of them making so much noise and moving around so energetically that he couldn't begin to count them. He'd known Yuma had a lot of friends, but seeing them all under one roof was a little overwhelming. For his last birthday, his mother had taken him to a nice restaurant. It had been so quiet he could hear his neighbors' forks hitting their plates. These people couldn't have heard an avalanche approaching, because they all seemed to be shouting at each other.
In a corner, he could hear Kaito hectoring someone Fuya dimly recognized as Thomas Arclight.
"...only reason he invited you was because he knew you rich boys would give him good presents," he was saying.
"Who are you calling a rich boy?" Thomas retorted. "Your father owns the damned city!"
An enormous man carrying a tray of cupcakes went barreling past, pursued by Kotori.
"You put those back!" she shouted.
"They're not for me! They're for Ponta!" he shouted back.
Fuya stared. He'd always been brought up to behave himself, to be polite, to never speak loudly unless the script called for it. It shocked him to see so many people raising their voices at each other, and apparently enjoying it.
A wiry dark-skinned boy, whose green eyes were partially obscured by his wavy black hair, came over to size him up.
"You're that actor kid." He made it into a challenge.
Fuya swallowed hard. "That's right. Yuma invited me to his birthday."
"Oh, yeah?" said the boy. "Well, fine, but I'm sitting next to him, so you have to sit somewhere else."
Fuya was aware that people were watching him, waiting to see what he'd do. Feeling astonished at his own daring, he gave the boy a shove, and watched his eyes widen as he was forced backwards. After years of training for stunts, Fuya was stronger than he looked.
"He's got two sides, doofus," Fuya said.
The boy stared at him a second, then laughed. "Okay, you're all right." He grinned and slung an arm around him. "Come on. Let's go grab the good seats before everyone else beats us to it."
Fuya grinned back. He thought he could get used to this kind of fighting.