The Two Sisters (Shadow x OC; MY BIRTHDAY SPECIAL!!!)

Chapter 1: The Invitation

It's been a while since Sonic and his friends faced difficult challenges and obstacles. Now, peace had been restored and everyone was doing their own businesses. Sonic was relaxing on a grass in the park. Team Dark was out on a G.U.N. mission. The Chaotix were having their day in the Chaotix Detective Agency Office. Knuckles was guarding the Master Emerald in Angel Island relaxing on top of the staircase. Tails was working on his new invention in his workshop. Silver was having a great time in his restored future. Same goes with Blaze in her dimension. Amy, Cream, Cheese, Chocola, Gemerl were hanging out in Central City while Vanilla stayed at home looking out the window.

One day, while Sonic was relaxing on the grass, a wind blew past him and an envelope landed on his feet. He opened one eye and spotted it. As soon as he did, he grabbed it, opened it and his eyes widened as it was an invitation to someone's birthday party

You are cordially invited to Runa's 16th birthday party and Aleyah's 14th birthday party. Please join us as we'll have a blast celebrating it!
Place: In a small cottage in Forest Hill
Time: 3:00pm-8:00pm
R.S.V.P.: ××××-××××-×××× (Pearla the Hedgehog)

Sonic smiled at it saying,"Hmm, sounds like an invitation to the party. I'd better tell the others".

Then, he sped off to tell the others thinking that if he didn't, they would most likely worry about him.

In Tails' workshop, he received the same invitation that was placed on his desk last night. Just then, Sonic ran into his workshop telling them that he'll go to the party of two sisters.

"Hey, Sonic! I received the same invitation! Can I come too?", Tails asked him.

"Of course! We'll totally have fun there!", answered Sonic,"Oh well, gotta go for a run".

Then, he took off to ask the others, one by one, if they received the same invitation.

Meanwhile in Angel Island, Knuckles read the same invitation sitting on top of the staircase, A party, huh? There's something fishy about it.

In Central City, Amy, Cream and Gemerl were carrying their shopping bags with Cheese and Chocola following them when they received the same invitation through Gemerl's software.

In the Chaotix Detective Agency Office, Vector got a call from someone named Pearla the Hedgehog saying that they're cordially invited to the two sisters' birthday party and she told him the same details from the invitation card. After that, he hung up and Charmy asked him,"What's the problem, Vector?".

"It's not a problem, Charmy. We're invited to a birthday party!", he answered happily.

"Oh yeah! A party!", Charmy cheered, overjoyed about it.

"Who, where and when are we celebrating?", Espio asked him leaning on the wall with his arms crossed.

"We're celebrating Runa's 16th birthday and Aleyah's 14th birthday at the same party. It will be held in a cottage nearby Forest Hill and we're gonna go there today at 3pm to 8pm", explained Vector.

"Alright! Let's do this!", said Charmy flying near the other two in excitement as he and the others got ready.

Meanwhile, in the G.U.N. Fortress, Team Dark came back from the mission, then the commander called them for something important. When they arrived at his office (with Shadow's arms crossed), he told them the same details the invitation card had.

After that, Rouge was the first one to respond,"I'd love that! It'd be nice to come to their birthday party".

"Affirmative", E-123 Omega agreed.

"Pass", he said in a blank expression.

"Figured. Someone named 'Runa' added that she felt like you're not big on parties", said the commander,"But she also said that her younger sister Aleyah insisted that you should come. You wouldn't want to regret this, will you?".

After a few moments of convincing Shadow to go to the party, he sighed and said,"Fine. I'll go".

Somewhere in Blaze's dimension, she received the same invitation from her bodyguard named Gardon and somewhere in the future, Silver received the same invitation for unknown reasons with an addition to time travelling to the past. And they both headed to the cottage with their powers.

Meanwhile, with Sonic, he went from place to place to tell his friends that he got an invitation. Whenever he found one (or some), they said they had the same invitation. After a few conversations, he sped off to another place looking for another friend. After the whole situation, he sped off to a party.