I do not own Digimon. I'm not sure what exactly inspired this, but…here it is. I know there isn't a lot of romance in this first chapter, but there will be more. I think. I'm sure.

Chapter 1: Like a Black Reflection

Gatomon was a happy Digimon. She was partnered with the undoubtedly most caring of the DigiDestined, Kari Kamiya. She was also madly in love with the Rookie-level Digimon, Patamon, who had the heart of a thousand Champion-level Digimon. She was surrounded by amazing friends, too. Life was easy. Until, one day…

"Okay, I love you, too. No, you hang up first! No, you! You, silly!" Gatomon giggled on the phone. She was talking to her beloved Patamon. "No, you hang up first!"

"Why can't they both just hang up at the same time?" Agumon wondered aloud. "It'd solve this problem, not to mention deduct the cost on the phone bill…"

Finally, Gatomon hung up. She smiled, saying, "Well, I lost this round."

"You make talking on the phone sound like sparring," Agumon tilted his head.

"Speaking of which, want to go around?" Gatomon asked, winking, "I promise I'll go easy on you."

"I think I'll pass this time."

"Suit yourself."

There was a knock on the door. Gatomon, with her cat-like reflexes, jumped up to get a glance through the peephole. It was Gennai. Gatomon squealed with delight. She assumed that he had come to return her tail ring to her. It had gotten damaged in a fire, and Izzy had to send it to Gennai. In the meantime, Gatomon would wear a ring given to her by Patamon, who worked hours on end just to afford the ring.

"Who is it?" Kari came out an asked.

"It's Gennai! He must have fixed my tail ring!" Gatomon exclaimed happily. As much as Gatomon loved the ring Patamon gave her, there was nothing like the original.

"That's great!" Kari smiled. She opened the door. There stood Gennai. He was not alone. A black cat Digimon was also with him. She was wearing a straw hat, a pair of sunglasses, and a Hawaiian shirt. "Hi, Gennai! And who is this?"

"Hello, Kari. This is…" Gennai began.

The black cat Digimon walked up to Gatomon and gave her a hug. The mysterious black furred Digimon greeted, "Hey, sis!"

"Sis…?" Gatomon looked absolutely perplexed, and rightfully so.

"…BlackGatomon," Gennai finished. "BlackGatomon is like a subspecies of Gatomon, and that particular one happens to be your Gatomon's sister."

"Whoa! Really?" Kari couldn't help but smile. She found it very cool. Gatomon, however, did not.

"Why does she smell like LadyDevimon?" Gatomon asked, recalling her past encounters with her Ultimate form's counterpart.

"That's because I am LadyDevimon! She's my Ultimate-level form!" BlackGatomon explained, unnervingly cheery. She lowered her sunglasses. Unlike Gatomon, BlackGatomon had yellowy goldenrod eyes.

"Other than the eyes, clothes, and fur color, the resemblance is uncanny," Agumon remarked.

"Oh, this old outfit?" BlackGatomon gestured to her attire. "It's just something goofy I wanted to put on to lighten the mood. I figured she'd smell LadyDevimon, so I wanted to do this to show that those days of troublemaking with Daemon and the Dark Masters are as good as over. I don't normally wear this."

"Why should I believe what you have to say?" Gatomon asked coldly.

"I can support her claim," Gennai offered. "Oh, before I forget, I brought this." He held up a Holy Ring.

"My tail ring?" Gatomon asked, not sounding as excited as she wanted to be. It was hard to be excited when you found out moments prior that your archrival is really your long-lost sister.

"That's great! Thank you, Gennai!" Kari thanked him and accepted the ring.

"Well, I'll be off. I've been quite busy lately," Gennai bid them farewell and disappeared.

"So, Gennai tells me that you're in a very serious relationship with a boy," BlackGatomon purred at Gatomon, who blushed at the comment. "How's the mating?"

"I'm not answering that! Geez! No sense of privacy?!" Gatomon snapped.

"You and Patamon have…?" Agumon began to ask.

"No!" Gatomon groaned in frustration.

"No need to get so touchy, sis," BlackGatomon giggled. Hearing BlackGatomon refer to her as "sis" made Gatomon's skin crawl. How could it be true? They were polar opposites! An angel and a devil. And yet…they were sisters?

"I still don't trust you," Gatomon growled. "Frankly, I don't think I even have a reason to."

"Gatomon!" Kari scolded. Gatomon looked at her human partner in shock. How could she side with a devil?

"I don't blame you. Got any fish?" BlackGatomon smiled. "Or grapes?"

"Sure! We have grapes!" Agumon went into the kitchen to fetch some grapes.

"So, what have you been up to lately?" BlackGatomon asked curiously.

"Not much…" Gatomon answered bitterly. She wasn't thrilled about the surprise that came in the form of BlackGatomon, but she would have to live with it. "You?"

"Not much, other than defecting from Daemon's army. Now, we're both renegades," BlackGatomon answered. Gatomon wondered how BlackGatomon knew about her history with Myotismon, and even more so, how much else she knew. BlackGatomon continued, "Every Digimon knows about how you betrayed Myotismon and became the Angel of Light. I can say 'My sister's with the DigiDestined'. At first, I didn't get why, but then I decided to break away from Daemon, and everything made sense."

Yeah, to one of us… Gatomon thought in her mind. Still a little shocked and very wary, she hoped that BlackGatomon wouldn't cause any trouble, or there would be heck to pay. Looking at BlackGatomon was like looking at a black reflection.

"As expected, you're just as pretty as me!" BlackGatomon smiled. Gatomon found her newfound sister's comment to be conceited.

"They're kind of like twins," Agumon muttered to Kari.

"Yeah, only with different fur and eye color," Kari whispered back.

Later that night, after a nice fish dinner, Gatomon called Patamon for consolation. She told him, "I'm not so sure I like this. You understand, right?"

"I can see why you'd be cautious and uneasy. On the other paw, I don't think it would hurt to try and accept her. You might even learn if she has any bad intentions," Patamon suggested.

"Are you saying I should trust her?" Gatomon asked.

"If she says she left Daemon, then yes. I have to admit, some of us were a little wary of you after you left Myotismon, but I never doubted you. I trusted you," Patamon made a connection that really hit it home.

"…Alright. For you," Gatomon conceded. She hung up and started humming. She figured that Patamon would have her best interest in mind, and she realized that he was right. BlackGatomon leaving Daemon was a lot like Gatomon leaving Myotismon. Even so, she hoped she wouldn't live to regret the decision to try to open up to her new sister.