Ash Ketchum's world had just gotten a whole lot bigger. A new adventure had begun for the Pokémon World Champion, and it was unlike anything he had ever experienced. He had been introduced as the latest addition to the Super Smash Bros. Ultimate roster, and while the honor was incredible, it was also a bit overwhelming. Ash stood on the front steps of the grand Smash Mansion, Pikachu perched on his shoulder, eyes wide with curiosity. The mansion's large doors creaked open, and out came Mario, his trademark red cap and blue overalls a beacon of familiarity.

"Hey, it's-a me, Mario! Welcome to the Smash Mansion, Ash!" Mario greeted enthusiastically, extending his hand in a warm, welcoming gesture.

Ash smiled, shaking Mario's hand, still processing the surreal situation he found himself in. "Wow, this place is huge! Thanks for having me, Mario!"

"Of course! You've been a top trainer for years, and we're excited to see you join the roster," Mario said, grinning from ear to ear. "Come on in! I'll show you around."

Ash nodded, feeling a mix of excitement and nervousness. This was a different kind of challenge—no wild Pokémon to capture, no Gym Leaders to defeat, just a whole new world of fighters, each with their own unique abilities. Pikachu twitched its ears in agreement, sensing the change in the air.

Inside the mansion was even more impressive than the outside. Huge hallways, high ceilings, and rooms decorated in a variety of styles, each representing a different fighter. There was a massive kitchen with a pizza oven, a vast training hall, and—naturally—a game room with an impressive collection of arcade cabinets and gaming consoles. As they walked down the hall, Ash noticed a group of familiar faces. Cloud Strife was standing in front of a mirror, adjusting his Buster Sword, while Link was seated on a bench, polishing his shield. Nearby, Samus Aran was discussing something with Donkey Kong, and Yoshi was munching on some fruit, his eyes gleaming with curiosity as they approached.

"This place looks amazing!" Ash said, his eyes wide with admiration.

Mario chuckled. "We all make ourselves at home here. But be warned—things can get a bit… chaotic. Just ask Peach and Daisy!" He gestured toward a pair of energetic figures approaching from the opposite direction. Princess Peach and Princess Daisy waved, with Daisy already grinning mischievously.

"Ash! It's so great to finally meet you!" Peach exclaimed, her bright smile lighting up the room. "We've heard so much about you!"

"Yeah, and we're ready for some fun!" Daisy added with a wink.

Pikachu perked up at the sight of the two princesses. "Pika pika!" it squeaked, offering a friendly greeting.

As they continued the tour, Ash began to feel the weight of being surrounded by such powerful and eccentric personalities. It wasn't just a matter of fitting in—it was more like figuring out how to navigate a world where every fighter had their own agenda, quirks, and abilities.

"Alright, I'll show you your room now," Mario said, guiding Ash up the staircase. "You'll be sharing with a couple of others. Trust me, it'll be fun. Well, mostly…"

Ash raised an eyebrow. "Sharing a room? With who?"

Mario smiled nervously. "Well… let's just say it's a bit of a 'family' situation. But don't worry! You'll fit right in!"

As they reached the top of the stairs, Mario stopped in front of a large wooden door, opening it to reveal a spacious, yet somewhat chaotic room. The walls were decorated with various posters of different fighters, and there were a few scattered pieces of equipment here and there. But what really caught Ash's attention were the two individuals sitting on the bed.

A tall, imposing figure with spiky hair and a massive sword was lounging on the bed, and beside him was a small, fiery-eyed boy holding a bat that looked a bit too big for him.

"Meet your roommates!" Mario said with a grin. "Cloud and Ness."

Cloud looked up, his blue eyes meeting Ash's. "You're the new guy, huh?" He sat up, giving Ash a once-over. "It's nice to have a normal fighter around. Hope you can handle the craziness around here."

Ness nodded in agreement, though his smile seemed a little mischievous. "You're gonna love it. Just make sure you don't get caught in any of the pranks… or explosions."

"Explosions?" Ash asked, raising an eyebrow.

"Let's just say that the atmosphere here can get… explosive," Cloud said with a smirk. "You'll see soon enough."

"Pikachu and I are up for anything!" Ash declared, trying to sound confident despite the overwhelming vibe.

The door to their room slammed open, and suddenly a whirlwind of activity engulfed them.

"Hi, everybody! I'm here! And I brought my sword! And my bombs!" shouted a familiar voice.

Ash's eyes widened. "Wait, is that…?"

"Yep, it's Link," Mario said with a sigh. "He loves to show off his equipment. You'll get used to it."

Link bounded in, already unsheathing his sword and knocking over a few items on the floor. "Hey, Cloud, Ness, you guys ready for some training? Let's see how the new guy handles it!" He turned to Ash, his face eager. "I'm Link! Hope you're as good as they say you are!"

Before Ash could even respond, a loud crash sounded from down the hall.

"Mario! Where's my room!?" shouted a voice that echoed through the mansion.

"That's probably Ganondorf," Mario mumbled, rubbing his temples.

Ash blinked. "Ganondorf?"

"Don't worry about him," Cloud said with a dismissive wave. "He's loud, but he means well… sometimes."

Suddenly, the door burst open again, and this time it was none other than the very excitable King Dedede, who waddled into the room with a grumpy face.

"WHO'S READY FOR SOME FUN?" Dedede bellowed, lifting a massive hammer that could probably flatten a few walls. "I've been hearing about all these new fighters! I wanna see some action!"

Pikachu flinched, hiding behind Ash, who gave Dedede a cautious look.

"Uh… fun sounds great," Ash said, trying to be polite. "I'm just… getting settled in."

"Settle in?" Dedede scoffed. "No time for that! We're gonna train hard, eat well, and cause some chaos around here! Welcome to Smash!"

As the madness unfolded around him, Ash felt the weight of what he had signed up for. The Smash Mansion was a chaotic, ever-changing world where the fighters were always on edge, always ready for the next battle. He could already tell that fitting in wasn't going to be easy, but he wasn't one to back down from a challenge.

"Looks like I've got a lot to learn," Ash thought, glancing at Pikachu, who gave him a reassuring smile.

And so, Ash Ketchum, the Pokémon Champion, began his new life in the Smash Mansion.