Author's Note: So I was looking through other fanfictions, and much to my surprise, there hasn't been one crossover fic between Kipo and Sonic the Hedgehog. Being a Sonic fan myself, I decided to correct this mistake by writing this.

Now, one thing you should know is that I haven't yet finished the series. I'm close to finishing season 2, but I'm a little impatient on uploading this. I'm quite excited about this.

As for the Sonic Underground theme, I was trying to figure out what variation of Sonic to use. I then realized that music was a major element in the Kipo show, and since I liked Sonic Underground as a kid, I figured this would be the best fit. As such, I'll be making this a musical. Some songs will be from Sonic Underground, some from Kipo, and some will be from other sources which I plan to make a parody off. I will not own any of the original songs and I don't own anything from Sonic the Hedgehog or Kipo and the Age of Wonderbeasts.

Now, I know this is a Sonic Underground crossover thing, but that doesn't mean I'll just use Sonic characters from Underground. I also plan to use Sonic characters that aren't in Underground.

As you can tell, the song featured here is Someday from the original Sonic Underground show.

I'm looking forward to this story. Any and all comments are welcome.

Two-hundred years.

That's a lot of time after the world was turned upside down. No one knows exactly why it happened, but one thing's for sure: after that, the world was never the same again. Whole cities were overgrown into a jungle with chaotic properties. Humans were hidden if not enslaved. Animals formed their own civilizations as mutants, or mutes. This didn't seem like a safe world to live in. That is, except for one girl: Kipo Oak.

Kipo may not look like a normal teenage girl, but she was certainly raised like one by her father, Lio. Despite her purple appearance, it never bothered anyone in her underground burrow of other humans. She was happy, made many friends, enjoyed the music she and her father made, and gained a stellar education by her father. Though she was told how dangerous the surface was for humans, she had always fantasized about seeing it.

One morning, Kipo stretched her arms and emerged from her bed. She was ready to face the day. She went to her father to say good morning, but she found him still asleep.

"Wake up, Dad." She said kneeling down next to his bed. "Time to get up."

Kipo lowered her hands to shake him awake, but they never stopped when they hit him. Instead, they went right through him like a ghost. Kipo's eyes widened trying to touch her father again, but like before, she went through him. She tried one more time with the same result.

Kipo yelled taking a step back. She took a deep breath trying to understand what was happening at the moment. She ran back to her room, but shrieked once more to see herself laying on the bed. Kipo looked down at herself in a confused tone before looking back at the look-alike in her bed. She stepped back into the hallway nearly out of breath.

"What's happening?" she panicked. "This… This has to be a dream, right? It's all in my head."

"This is a dream, Kipo, but it's far from your head."

Kipo's eyes widened as she heard the voice coming from her left. She turned to the living room where she found someone glowing green. But this person wasn't human; he looked like a green anteater in a black hood.

Kipo yelled again falling back. "Who are you? What is this? Why is this happening to me?"

"It is quite all right, Kipo." The anteater said. "I bear you no ill will."

"How do know my name?" Kipo asked.

"Why, I've known your name for as long as I've known your father. As for me, I am the Oracle of Delphius."

"Oracle?" Kipo asked. "And you know my dad? Nothing about this makes sense!"

"I understand, and I'm sorry for meeting you in this state." The Oracle said. "I don't exactly know where your burrow is. This seemed like the best way to talk to you."

Kipo slowly stood back up on her feet. "You want to talk to me? About what?"

The Oracle put on a serious face. "Big changes are about to happen. Your world is going to change in ways you can never imagine. And when it does, you must seek out everyone else you're bonded with."

"Bonded with?" Kipo asked. "What does that mean? And what changes?"

The Oracle didn't answer that last question. He simply pointed at the guitar that rested in the living room corner. "Pick that up and start playing it. You'll find those you must seek."

"By playing a guitar?" Kipo asked with reservations.

"Just try it." The Oracle said.

Kipo was still confused, with both the words and the situation. Still, she figured that it was pointless to keep questioning. She walked over to the guitar and wrapped her hands on it. Much to her surprise, she was able to lift it up.

"This doesn't make sense." Kipo said. "How come I can carry this but I still can't touch my dad?"

"That's not important." The Oracle said. "Just play."

Still curious, Kipo wrapped the guitar around her and prepared to strum. "What do you want me to play?"

"Anything. Just start and you'll know."

Kipo began by playing one string on her guitar. When nothing happened, she kept playing at random. At first, it didn't seem like anything, but after a while, the music she played stop being random. This was a music that she's never heard of but was playing masterfully.

The background then blackened. A spotlight shined revealing three mute hedgehogs. One had blue fur, wore red shoes with white stripes, and played an electric guitar. There was also a pink girl hedgehog who dressed fancy and played a keyboard. The green hedgehog played a drumset while wearing street clothes. They all played the same song and Kipo was somehow enthralled by the music enough to play alongside them.

The song started and the blue hedgehog began to sing.

Blue hedgehog:

There's something missing

Something's not quite right

And I can feel it calling

To me every night

Kipo:

A little voice inside

Tells me someone is out there

And I must never give up

Searching everywhere

Everyone:

Someday

We are gonna be together

Someday

Life will be so much better

Someday

We will build a bond no one can break

Someday

No more dark clouds above

Someday

United in the light of love

Someday

The story can only end one way

We'll be together someday

SOMEDAY

WE ARE GONNA BE TOGETHER

SOMEDAY

LIFE WILL BE SO MUCH BETTER

SOMEDAY

WE WILL BUILD A BOND NO ONE CAN BREAK

SOMEDAY

NO MORE DARK CLOUDS ABOVE

SOMEDAY

UNITED IN THE LIGHT OF LOVE

SOMEDAY

THE STORY CAN ONLY END ONE WAY

WE'LL BE TOGETHER SOMEDAY

SOMEDAY

WE'LL BE TOGETHER SOMEDAAAAAAAAAAAAY

Kipo gasped as she woke up in her own bed. The song the played with the hedgehogs still played in her head, but with no guitar around, she had no idea where it came from.

"Hey, Kipo." Lio said as he stood in the doorway. "Ready for our climb?"

"Uh… Yeah, Dad." Kipo said in a confused tone.

"Is something bothering you?" Lio asked.

"No, no. I'm just… tired, I guess." Kipo lied. "I'm ready."

"All right." Lio said.

Though she still had the strange dream on her mind, Kipo had a lot of fun climbing the rock wall with her father tethered behind her.

"Today's the day." She said to herself. "All the way to the ceiling."

"What's the holdup, slowpoke?" Lio asked his daughter from below.

"No holdup." Kipo said chuckling nervously. "Why? Does it look like I'm holding up?"

"No, you are clearly not holding up." Lio said playfully. "But while we're waiting, tell me, what minerals are in most abundance at this stratum?"

"Dad, that's easy." Kipo said. "Azurite and malachite, two of my favorite 'ites'."

"If you can ace a pop geology quiz, then I know you can make it the rest of the way." Lio said.

Taking her dad's words to heart, Kipo continued her climb. One moment later, the ground above them began to shake along with a distant booming sound.

"Just a Mega Mute passing overhead." Lio said. "Little close, but nothing to worry about."

The footsteps of the Mega Mute above ground continued. While everyone was paused, Kipo turned to her dad.

"Hey, Dad," she said, "Since we're here, can I ask you something?"

"About what, baby girl?"

"Well, this is gonna sound weird, but I had this strange dream. There was this green anteater guy in a robe…"

"Anteater?" Lio asked with concern starting to form on his face. "Uh… What did this anteater dream say?"

"Well, a lot of strange stuff," Kipo said, "But the strangest thing was when I started playing some kind of song along with three hedgehog mutes."

Lio's mild concern quickly changed into panic. That's when he heard the Mega Mute roar sounding like it was getting closer.

"They found us." Lio gasped quietly. "The prophecy…"

"What was that, Dad?" Kipo asked.

Lio didn't hesitate. As the rumbling noises became more frequent, he grabbed onto Kipo's rope and pulled it roughly. Kipo lost her grip as she fell off. Thankfully, she landed in the water stream where he was aiming. Lio jumped down to follow her, but before he could reach her in the stream, he noticed big rocks that would stop him falling from the ceiling. With very little option, he held up the black bag he carried and tossed it.

"KIPO, CATCH!" he yelled. "DON'T LOSE IT!"

"WHAT?" Kipo asked just as he bag hit her chest. She fell into the dark chasm where the stream fell right as the rocks blocked the way in front of her father.

"This is bad." Lio gasped. "I knew this day had to come, but now that it's here…"

He stopped when sunlight hit his face. He looked up and a crack formed and grew in the ceiling. That was when a large tree with scratch marks stabbed right through in front of Lio. It was pulled out, and the red eye of a Mega Monkey peeked into the hole it made.

From one stream to another, Kipo yelled as she tried her best to keep track of her course. It was hard to with all the twists, turns, and spirals, especially when she kept getting splashed by the rapids she rode.

In only a matter of minutes, the water burst through an open sewer pipe in the surface. Kipo finally found a moment to breathe only to find out where she ended up.

"I'm on the surface!" Kipo panicked. She was nearly blinded from looking at the sun, but recovered. Kipo tried to go back through the stream she came from, but with all the rocks in the way, there was no use.

"DAD, CAN YOU HEAR ME?" she tried calling out. There was no answer, which made her slum down. "Of course not. He must be miles away. Okay. You got this, Kipo. Humans lived on the surface for thousands of years. You can handle a few minutes up here. You just have to find your way home. Hey, what's this?"

Kipo remembered the black bag her father threw at her. She carefully opened it up and pulled out the solid object that was glowing inside. She was captivated by the gemstone that was the same color as she was. It illuminated divinely.

"Well, this is strange." Kipo said. "Why would my dad have something like this? I guess I'll ask him when I see him."

In another part of the city, not too far from where Kipo was, a lone, blue hedgehog in red and white shoes strummed on his electric guitar. He played a familiar song.

"The story can only end one way. We'll be together someday…" he sang before talking normally. "Man, that dream last night was plenty weird. Who were those other guys?"