This is the spinoff of my Amiamon x Rin fanfic "Demon Heart". It literally continues where that fic left off. I hope you guys enjoy the forever infamous Mephisto x Yukio pairing! Mwahahahahaahhaaaa Oh and I don't own Blue Exorcist

ANNND thank you to the wonderful Flamefox2 for being my wonderful beta and correcting my oh so simple errors.

Yukio sips the glass of red wine as he stares at Mephisto's back. The demon king appears to be in deep thought. He looks out of the window over the campus, not speaking. Yukio stands, twirling the blood red liquid in his glass. "I'm going to go back to my room. There are a few things I need to do to prepare for class tomorrow."

"Yes, of course," Mephisto says, not turning around. "Class... you teach a class with that female you were involved with."

"Female? Oh, you mean Shiemi." Yukio stares down sadly into the glass. "We are no longer involved."

"Oh?" Mephisto turns around. "Did something happen?"

"I lost her trust. After everyone found out about Rin."

"Really? Well, with your charms and good looks, I'm sure you can get her back."

Yukio chokes on his drink. "Wha-?"

"You heard me! Win her back!"

He looks away, somewhat angry. "I don't want her back."

"Oh?" Mephisto walks around his desk and towards Yukio. "Why is that?"

"Because I just don't want to."

"You're lying. Ever since Amaimon disappeared you've been wanting to know how it feels to love the way Rin did. Sure, you're happy that Amaimon and Rin are together now, but you're also so envious."

"Whether you're right or not - which you're not - it doesn't mean Shiemi is the person I want to love!"

"They who might it be?"

"I don't know! I don't even know how it feels to love anymore."

Yukio rolls his eyes and starts to take another sip of his wine but Mephisto swipes it out of his hand. "You've had enough. You've got things to do, right?"

"Yeah. Thanks. I'll talk to you later." Yukio walks out of the office, Mephisto's eyes following him curiously. The demon king takes a sip of the red wine he took from Yukio.

"You're way too innocent for your own good." Mephisto walks back to his desk and sits in his chair. He closes his eyes and recalls the previous night. He'd gotten Yukio in his office the entire night. He was drunk for the first time in his life. He'd talked so much about Shura and Shiemi in a daze and he'd acknowledged the door to Gehenna being open so he wasn't that far gone, but he wasn't sober enough to question it. The one thing that shakes Mephisto the most are words he said just before he'd passed out."Mephisto, you're a demon, so why am I so comfortable around you?"

Mephisto shakes his head viciously, removing the thought and softness that comes with it. "That brat isn't human, he didn't even have a hangover when he woke up this morning."

"Who are you talking to, Brother?" Mephisto flinches at the sudden sound of his brother's voice.

"Amaimon, why don't you knock before appearing behind people?"

"That's no fun."

"What are you doing here? Shouldn't you be having reunion sex with Rin or something?"

"No. We did that last night. Rin is going to play with his friends today and he doesn't want me to scare them."

"Tch foolish Esquires." Mephisto stands from his chair. "Too in denial to accept that demons run Assiah from the inside out."

"Yep."

Mephisto looks over at Amiamon to see him sitting on the pink couch with a lollipop in his mouth. "Are you ready to go back to Gehenna?"

"I don't want to."

"Yes, of course you want to stay here and cause more trouble." Mephisto grabs his pink umbrella. "I'm going out, so stay put and don't blow anything up."

"Can I come with you?"

"No. You're too obvious"

"Pleeeeeaaaaaaasse!"

"I said no."

"Pllleeeeeeeeeeeeeeeeeeeeeeeeeeaaaaaaaaaaaaaaaa-"

"OK, SHUT UP! You can come..."

"Yaaay!" Amaimon poofs into a hamster and hops into Mephisto's front jacket pocket. Together they leave. The weather on campus is nice as usual with the sun shining brightly. Students wander the campus laughing and smiling, many of them recognizing Mephisto - not as himself, of course.

"Good morning, Principal!"

"Well, good morning to you!"

"Good morning, Mr. Faust!"

"Good morning, student!" His voice is super jolly despite not actually feeling any happiness towards the human children. He walks down a flight of stairs and through a huge arch, coming to a sudden stop upon seeing Yukio and Shiemi. He ducks back around the corner. He uses his demon ears to hear their conversation.

"Yeah. He's much better now," Yukio says.

"That's a relief to hear. He's been so bothered lately, not talking to anyone. I'm glad he is back to normal."

"Yeah, me too."

The two are silent for a few seconds. "Yukio... about us. I just wanted to say sorry. I guess I was just a little scared..."

"No Shiemi, you don't need to apologize. It 's my fault. I should've had more trust in you."

With a puff of smoke Mephisto changes into a dog and Amaimon drops on the ground next to him. They casually approach Yukio and Shiemi. "Oh... well, all right. Uhm... , I was just about to go play a game of... OH MY GOD, its so cute!"

Yukio turns around to where Shiemi runs and that's when he sees the purple dog and green hamster. He recognizes the hamster too as the one that has been in his room with Rin for the past 2 months. He also knows Mephisto has two forms himself. A cockroach... and a cute dog. "Oh, why..."

"Aren't you the cutest little things in the world! Are you lost?" Shiemi pets the dog and the hamster. She looks back at Yukio. "Aren't they just the cutest things?"

"Adorable." No sign of adoration is on Yukio's face. "So what were you saying, Shiemi?"

"Oh! I was about to go play baseball with the others. I wanted to know if you wanted to come along, too. Just me, Rin, Bon, Konekomaru, Izumo, and Shima."

"Oh... sure."

Shiemi jumps up. "Oh! I'm late! I need to go." She looks down at the dog. "But I can't just leave them here... Yukio, do you think you can help them find their owner?"

"Sure thing. Go on. I'll take care of them."

"Great! We are going to be at Mika Park at twelve! See you later!" She runs off with a bag of stuff that she'd been carrying. As soon as she is out of sight, Mephisto changes back into his human form, as well as Amaimon.

"What the hell are you doing here?" hissed Yukio.

"I was actually heading to meet an important person and then I stumbled upon this beautiful scene," replied Mephisto with a smirk.

"So you interrupted it."

"From what I was hearing, I helped you out."

"Whatever."

"She said you were playing game!" Amaimon smiles. "Can I come?"

"No, Amaimon," Mephisto and Yukio say in unison.

"Why not?"

"Do you not remember blowing up a court room?" asked Yukio.

"I died."

"Exactly!"

Mephisto puts his hand on his chin in consideration and smiles. "Maybe this is a good idea."

"What?"

"These Esquires, like the higher exorcists, need to know the truth. They have to know that demons are in their world and they need to accept it. What better way to do this than with a friendly game of baseball?"

"Are you serious, Mephisto?"

"Yes. You agree, don't you?"

Yukio looks to the side stubbornly. "Maybe you're right."

"I know I'm right."

"Yaaaay!" Amaimon leaps into the air.

An hour later, they are walking together to the large field of Mika Park. The Esquires are in the middle, swinging bats in practice and tossing balls. Bon is the first person who catches sight of the 3. "What the hell?"

Everyone looks at the group in disbelief. "Is that Amaimon?" Izumo gasps. "I thought he was dead!" Rin pays no attention to the others' shock and runs up to Amaimon, wrapping his arms around his neck. Amaimon pecks a kiss on his forehead, wrapping his arms around Rin's waist.

"Hello, brother."

Rin finally snaps out of his love struck daze and he turns around to look at his friends who have just barely accepted him. They are all standing with distraught expressions. "What are you doing here?" Rin whispers to Amaimon.

"We want to play!"

They walk closer to the others until they are standing face to face. 4 against 5. Demons and Exorcists. "He... hello, Principal Faust... I mean... Demon King Samael," Bon said uncertainly.

Mephisto laughs formally. "Oh no need for formalities, just call me Mephisto."

"What the hell are you guys doing here? And most importantly, why is he still alive?"

"Really, killing a demon king isn't easy and the story is way too long to explain right now. Think of our presence as a test of your exorcist abilities," Mephisto says with a devious smile.

Yukio steps up, speaking next before Mephisto scares everyone. "You Esquires aren't aware, but although you fight demons for a living, they are everywhere in the world working with and for us."

"More like leading you."

"Shut up, Mephisto. Today will be a prime example of how we coexist with demons: A friendly game of baseball. And not just any demon, but the Kings of Gehenna and spawn of Satan." Amaimon and Mephisto poof their clothes into something more sporty and suiting to the event.

"Don't worry." Mephisto grins. "We'll go easy on you." That being said, Mephisto, Amaimon and Rin all whip out their tails, truly looking like brothers. "No tricks."

"Yukio," Shiemi mumbles, barely heard. "Are you on the team with the demons?"

"Yes. I know them better." Mephisto rests his elbow on Yukio's shoulder, nearly knocking him over.

"Oh. Okay."

Bon looks at everyone's fearful expressions and gets pissed off. "OKAY! What are we waiting for?! Lets kick some demon ass!"

The game begins. Bon is first to bat with Mephisto as catcher and Amaimon on the pitchers mound. Amaimon has a straight face as he stares down Bon. "Are you ready?"

"Just throw the damn ball!"

"Ok." Amaimon twists his whole arm twice and releases the ball with flaming speed. Bon is not intimidated by this in the slightest. He grabs the bat tighter and swings. A huge pop is heard and then a yell. Everyone looks in the air for the ball but sees nothing. They then look back at Bon to see his steel bat broken and Mephisto on the ground.

Yukio scratched his head. "I think we will count that as a walk?" Bon shrugs his shoulders and drops the bat, walking through the bases. Shima's face holds pure amazement.

"The bat exploded..."

Mephisto finally sits up, a huge knot on his forehead. Amiamon points a finger. "Brother, your head is big." This makes Mephisto launch Amiamon, kicking him 12 feet into the sky. "Weeeeee!"

Bon looks at the floating demon. "What the...?" Suddenly Rin busts out into laughter. Amiamon lands on his feet.

"OK!" Yukio calls. "Rin, you're next to bat."

"Yeah!" Rin runs up with a new bat. "I'm ready!" Konekomaru shakes his way to the pitchers mound. "Come on, Konekomaru. Give me all you've got."

"O... okay!" He throws the ball and it practically floats through the air. Rin swings at it with all his might. I flies directly above his head. It goes up and up and up and up... and up. Everyone stares into the blue sky until the ball disappears.

"Uhm...?"

"Well," Yukio straightens his glasses, "I think that puts Rin out."

"What?!"

"There's no way to get that ball back. You fouled out in one swing.."

"Why, you-!"

"OK! Next up to bat is Izumo!"

Rin pouts out of the way and Izumo picks up the bat. She has the perfect batter stance. Yukio goes to the pitch, his glasses glaring in the sun as he concentrates. "I'm not going to hold back."

Izumo furrows her eyebrows, her stance becoming more defensive. "No one asked you to."

Mephisto smiles as he watches Yukio's concentration from beside Rin, who is the catcher. "He looks quite nice, doesn't he?"

Rin looks at him, raising an eyebrow. "What?"

Mephisto says nothing. Yukio throws the ball with great force and it curves in air. Izumo swings and misses. Rin catches the powerful toss.

"Strike one," Yukio whispers.

Izumo clenches the bat tighter and Yukio prepares for the next pitch. He throws it and this time it is a fork. Izumo swings.

POP

Yukio turns around. "Catch it!"

Both Amaimon and Mephisto leap into the air, practically taking flight but are not high enough and fall back to the ground. Mephisto goes for a nose dive and lands on his feet, putting a crater in the ground. He hits a sprint after the ball and flips in the ground. This kicks up a lot of dust and renders their sight. He leaps into the air with the ball and a cocky expression.

"YAHOO!" Rin leaps into the air.

"You're out!" Yukio yells in excitement.

Mephisto walks towards them.. He ran so far that it takes him a while to return. He finally gets close to the field with the others. Yukio runs and jumps on his back, putting his arm around Mephisto. "You're the best, Mephisto! That was great!" Mephisto looks at him and nods.

"I feel like you underestimate me."

"That's where you're wrong."

"Nice, brother," Amaimon states, not showing much excitement. Suddenly Rin jumps on Amaimon's shoulders with a huge smile, showing all teeth.

"That was awesome, Mephisto!"

The Esquires have raised eye brows and they gather, watching the four celebrate. Shima smiles. "Wow... Don't they look like they have too many emotions to be demons?"

"Yeah," Bon agrees. "I'd think they were human if not for the tails... and inhumane strength."

Shiemi smiles. "I think they're cute."

"WHA?" Everyone is surprised by her statement.

"Well, as a family! I mean, look at them. How often do you think demons get to play like this?"

The team turns to look at the family of demons, thoughtful. "Probably never," Konekomaru adds.

Bon steps up. "Would you guys shut up! We have a game to finish!"

*Two hours and 7 broken bats later*

Bon lays on the ground out of pure exhaustion. "Who the hell even won?"

"Awww," Amaimon groans. "Is it over already?"

Bon sits up in a rage. "Over?! You broke all of our bats!"

"Not my fault you have cheap equipment."

"They were metal!"

Yukio stands off to the side with Mephisto, laughing. "You know, this was actually a good idea. They look comfortable."

"Of course it was a good idea. I came up with it."

"I was worried they wouldn't accept you guys."

"Because they have a choice?"

"I guess you're kind of right." Yukio looks over to Konekomaru, Shima, and Shiemi.

"I see why you like her. She's a looker and is quite soft-hearted... A lot like you."

"What?" Yukio glances at Mephisto.

"You're willing to give everyone a chance. You look tough but you're as soft as a flower."

"I don't like her. How many times do I have to tell you that?"

"You don't have to tell me anything. I see the way you look at her."

"Dammit, Mephisto. What do you want from me?"

"To admit it."

Yukio pulls him further away, behind one of the many trees surrounding the field. "You want me to admit it? Really!? Fine. I'll admit that I liked her when I was with her. Then she dumped me and where was I? In your office. Every day. I lost interest in her because I was around you every day. Because I was envious of Rin and his relationship with Amaimon. I don't know how it feels to love. I can't know how love feels since I've never experienced it! When I'm in your office, you irritate me! When I talk to you, you annoy me! But I get sick when... when I'm not around you... and since I don't know how love feels I can't prove it, but I think... I think that's it. How I feel with you. You want me to admit it!? I think I - mmmmm!"

Before Yukio can finish his sentence, Mephisto yanks his arm and pulls him into a kiss. Yukio's eyes are wide, not expecting it. After a few seconds, he indulges himself and grabs Mephisto's arms. Their tongues go deeper in the others mouth, cherishing the taste. He feels his heart rate speed up and his stomach flips in adoration.

Gently, Mephisto slips out of the kiss, leaving Yukio breathless. "So what has it been? A month that you've loved me? I feel like you need more." Mephisto dips into another kiss, wrapping his arms around Yukio and pulling him closer.

"Wow!" The two look back and see Rin sitting on a tree branch. "I was suspicious but I really wanted to be proved wrong."

"Don't you have anything better to do?" Mephisto growls, not happy about being interrupted. Yukio steps away from Mephisto and straightens his clothes.

"We should get going."

"Yeah." Rin giggles. "So you can fuck Mephisto."

Yukio grabs Rin's foot and yanks him onto the ground. He face-plants into the grass. "As if you're one to talk."

"Actually," Mephisto clarifies, "I'll be the one fucking being that I'll be on top."

"WHOA!" Yukio has pure fear written on his face. "No!"

"Well, I'm no uke." Mephisto shrugs.

"Neither am I. I kill demons for a living!"

"I'm over a thousand years old and one of the most powerful demon kings in existence."

"But... but... I can't heal!"

"Yes, you can. Just not as fast as a demon. Besides, that will make it more enjoyable."

Yukio raises an eyebrow. "...Hey Rin, who's on top in your relationship?" Rin's face becomes nervous.

"Me of course," Amaimon answers, leaning on a nearby tree.

Yukio snorts a laugh. "Rin's a neko."

"Shut the hell up, Four-Eyes! You'll be one soon!"

"He's right, you know." Mephisto smiles.

The group of Esquires can see the little spat that they are having. Bon scratches his head. "So Yukio with Mephisto and Rin with Amaimon," he murmured.

"Did they really think that tree would hide them?" Konekomaru asks.

"That's gross," Shima comments.

"Even though Mephisto and Amaimon are demon kings, they are over 1000 years old. Does that make this child molestation?" wonders Izumo.

"Really?!" Bon yells. "They are brothers!"

Shiemi giggles. "I think it's cute."

"WHAAAA!?"

LLL- So yes. The impossible pairing of Mephisto x Yukio. Hope you enjoyed. I could add more but I think this would be a better One Shot