Hyodo Issei's parents were a great many things. The list didn't generally include stupid.

The father of one Rias Gremory had arranged for their modest four-bedroom house to be replaced by a six-storey mansion. Allegedly this was a 'model' home to demonstrate the capabilities of the Gremory's construction company but since no one ever actually turned up to inspect it...

"When fortune smiles, don't frown back," Mr Hyodo told his wife sagely. She quite agreed.

So when the same Rias Gremory collected the morning post and brightly handed over a letter saying that the Hyodo parents had won a cruise for two in the South Pacific theny'd simply arranged vacation time to take it and made no mention that this would coincide with Rias' graduation from high school.

"So how do you think the party is going?" Mrs Hyodo asked from where she was leaning on the rail of the balcony of their suite aboard the cruise ship.

"Oh is it that day already?"

"Yesterday was graduation day," she reminded her husband. "So today..."

"All Issei and Asia and Rias' friends will be there."

"And Akeno, Xenovia and Gasper's..."

He nodded and joined her on the balcony with two glasses of fruity drinks. "Perhaps I watched too much anime when I was Issei's age but I'd have expected with so many girls after him that they'd be fighting over him but that doesn't seem to happen."

"Silly man. If the girls were fighting then they'd be sure you didn't notice it. But you're right, even Irina-chan doesn't seem to mind the others and she has the childhood friend card to play."

"Maybe we've raised a good boy after all."

They exchanged looks and laughed quietly.

"Well I told him where to buy condoms before we left. If he at least remembers that..."

"They've had ample opportunities before," Mrs Hyodo pointed out. "Summer trips, time at their club building... if they're playing around like that then they've learned to keep from making any lasting mistakes. Besides, the Student Council President will be there and her older sister agreed to drop by today to make sure things don't get out of hand.

The two Hyodo's sipped from their drinks and looked up at the sky. More than two hours eastwards of Japan, the moon's now-eternal crescent was just coming into view.

"It's been almost a year now," Mr Hyodo mused, looking up at it.

The party that took place was rather more restrained than the Hyodo's expected - ironic since more than almost all of the participants were devils. Granted alcohol was flowing freely but most of the high-class devils were accustomed to and were served with high-class wines with their peerages following suite - and in any case Devil physiology is rather more resilient to intoxication than humans would be.

The worst property damage so far has been when graduating school president Sitri Sona's elder sister decided to turn the basement swimming pool into an ice rink.

Rias was reflecting on the success of the party as she lounged on a couch opposite her Pawn. Issei'd gone as crimson as her hair when Rias asked if he'd be her lap pillow for a while and it had been most enjoyable, even if Irina, Asia and now Koneko had demanded a turn as well.

Ah well, such was life with her adorable perverted pawn.

The vibration of her phone stirred Rias from these thoughts. When she opened it the number wasn't familiar. "Hello?"

"Hiya, Rias, long time no see."

"Karma!" she exclaimed, sitting up. "I haven't heard from you in forever!"

"I was doing a favour for your brother. Anyway, just letting you know I'll be dropping in on you."

"Really, when?"

"Right now." The call cut off.

She blinked. He wouldn't. Wait, of course he would.

"Is something wrong, Buchou?" asked Xenovia, the knight having apparently seen her concern.

"We're about to have another guest."

Even as she spoke a demonic circle appeared on the floor between the two couches. Across from Rias, Koneko sat up sharply and the top of her skull smacked against Issei's jaw , sending the young man sprawling backwards with a cry of pain.

A blaze of energy lit the circle, drawing the attention of everyone else in the hall and when the light faded the circle was almost covered in bodies.

Facing Rias at the edge of the circle, a human firearm in each hand, Karma Gremory shot her his familiar wicked smile. "Hey cousin, you didn't tell me you were throwing a party."

Behind him, on the other side of the circle a tall man with spiky black hair exhaled and half-turned. Rias heard in-takes of air as devils shook off their surprise and - peace or no peace - instinctively tensed for battle.

"Who're you?" demanded Issei, rising to his feet, one hand still clutching his jaw.

"The Smiling Malakim." Xenovia's voice shook. "Karasuma Tadaomi."

Rias stood and bowed slightly to the angel who'd unexpectedly arrived with Karma. "You're still making interesting friends, Karma."

"You know me." The boy - he was a good three years her junior - tossed the guns aside casually. "Hey, we might need those couches." He lifted one of the bodies - not dead bodies, Riase realised with some relief - and placed the pigtailed girl on the couch where Rias had been sitting a moment. "This one's mine."

He turned back and turned over a muscular boy. "Hey, did you pick Terasaka?"

Karasuma gestured for Issei and Koneko to get clear of the other couch and put a busty blonde woman on it. "No, you made him one of your peerage."

"Huh. Wonder why I did that. Must have hit my head or something."

Rias stepped forward and helped Karma disentangle a green-haired girl from where she was half-buried beneath the boy. "You have a peerage now, Karma?"

"Yeah." He rolled the boy over and out of the circle.

"I hadn't heard you'd been promoted to a high-class devil."

"I haven't been." He looked around. "The couches won't do. Got any beds in this place?"

"Of course." Rias looked at Issei and Koneko, who had already started to help grim looking angel with other arrivals. With the exception of the blonde woman, none looked older than the two young devils. "We've several guest rooms. Issei, Koneko, Xenovia, please help moving our new guests to beds."

Issei rubbed the back of his head. "Sure, Buchou." He took in the tattered clothes, particularly those on the girls. "Was there a battle?"

Karasuma and Karma exchanged looks. "No," the devil said, the smile slipping slightly into something uglier. "There was an assassination."

There didn't really seem to be anything much to say to that so Issei picked up a slightly built bleuette, Koneko took a tall blonde girl and Xenovia lifted a handsome boy still wearing the frames of broken spectacles out of the heap.

Rias found Serafall in Gasper's room, losing at some video game to the reclusive bishop.

"Leviathan-sama."

"It's Levia-tan!" protested the self-proclaimed magical girl and leant back far enough that she could see Rias. That meant that the Gremory heiress could see the exact moment that the Maou spotted Karma. "You!"

(Gasper tapped one more control, scoring some victory judging by the music blaring from the console and then dived for cover under the bed. A moment later he reached out and dragged his cardboard box under it with him.)

"Hey." Karma tilted his head back slightly and looked down at the raven-haired girl, heedless of the icy needles forming in the air above her. "Still mad?"

"I told you what I'd do if you ever came within a hundred miles of Sona-chan again."

The boy waved his hand casually. "You don't complain about the long nightly conversations I have with her."

"What long nightly conversations!"

"Sure, we've been discussing education theory..."

Rias cleared her throat. "Leviathan-sama, Karma says he's here regarding a project the Maou assigned him to."

"I don't know anything about a project," Serafall replied with a cruel smile and the needles of ice swelled in size and power. "Any last wishes, you hair-molesting scumbag?"

The yellow-eyed devil declined to sweat. "Give me your honest opinion." He held out his phone. "What do you think of her magical girl potential?"

"Ohhh... She's so adorable." The needles dispersed immediately. "Has she picked a transformation phrase yet!"

"Nagisa needs expert guidance," Karma said with a shrug. "She's in one of the guest rooms."

"Right!"

With a sudden burst of energy Serafall leapt to her feet. "You're spared, but only for a greater emergency," she declared and burst out of the room.

Rias squinted at the screen of Karma's phone. The little bleuette she'd seen earlier was sitting beneath a tree, wearing a school uniform skirt and sweater. She looked nervous and yes, admittedly, gosh-darned cute. "So is she your girlfriend?"

Karma seemed to find that amusing. "Just a friend. So, it looks like Leviathan is a wash. Should we bother your brother next?"

"Actually, I was thinking of calling Ajuka Beelzebub. After all, this does involve you having Evil Pieces when you're still a mid-ranked Devil."

"Well they were just lying around so I swiped them."

"Honestly, Karma, are you trying to anger all the Maou?"

"Not specifically, but it seems to be working out that way."

Chiba Ryunosuke opened his eyes and saw familiar green eyes looking into his. "Rinka-chan?"

She made a hushing sound and rested her forehead against his for a moment. "I thought you were dead."

A roar like explosives and the bus coming apart filled his mind. "So did I." He put his arms around her as if to check he wasn't dreaming.

"Mmm." Usually undemonstrative, she snuggled closer into the embrace.

Nothing else registered on the boy until he felt feathers. "What? Rinka... you have wings."

"Un. You too."

"And a halo."

"Chi-" She flushed slightly. "Ryunosuke-kun? I think we're in heaven."

"Oh."

"Uh-huh." Then she pressed her lips against his and Chiba Ryunosuke agreed that the heaven theory had a lot going for it.

"Why did you call him the Smiling Malakim?" Issei asked Xenovia as they put the last of the boys into a guest bed. Despite the large number of rooms available in the mansion, they'd had to put the new arrivals four or five to a bed to fit everyone in. Fortunately the beds in all the rooms were of a luxurious size that could easily accomodate multiple occupants.

"Karasuma-sama is a legend among the Heaven's Exorcists. It's said that only the devils he's slain have ever seen him smile."

"Really?"

"And it's supposed to be so terrible that some of the devils died of terror."

Issei whistled. "Have you ever met him before?"

"Only once. He works directly for the Seraphs. One of my teachers fought alongside him once and she had a photograph."

"Scary." Koneko slipped one hand into Issei's.

"It's okay, he's one of the good guys, right?"

Xenovia pursed her lips. "You mean regarding the Khaos Brigade? I wouldn't have thought he'd side with them. He's said to be faultlessly loyal."

"Thank you." Karasuma put the phone down across the room and ignored the colour flooding across the faces of Rias' peerage. "I appreciate you welcoming us into your home, Hyodo Issei."

"Eh, it's fine." Issei's free hand crept up behind his head. "You were in need, right?"

"Yes." He took out his cellphone. "Ritsu, do you have a report?"

"I've recovered 99.998% of the data that was available on my main unit before it was destroyed," a girl's voice replied from the speaker.

"Thats good. Is there anything in the news about our coach?"

"There's a traffic warning and a diversion around the area."

"That's very discreet." He turned the phone towards the trio. "Ritsu, these are some of our hosts: the peerage of Rias Gremory."

On the screen a violet haired girl in the middle of an idyllic woodland bowed to them. "Hi. My classmates call me Ritsu. I'll be in your care."

"Hyodo Issei, but call me Ise! Pleased to meet you, Ritsu-chan."

Koneko elbowed him. "You're the worst," she hissed. "Toujou Koneko of Rias Gremory's peerage."

"I'm Xenovia Quarta. Um... you said 'main unit'?"

"Yes," the girl replied brightly. "I'm the Autonomously Thinking Fixed Artillery, or 'Jiritsu shiko kotei hodai'. My main unit was on the coach with everyone else but I have distributed back-ups."

"You're... a machine?" the knight asked in confusion.

"Yes!"

Karasuma cleared her throat. "She appears to be fully autonomous and has acted against her designer's directives. For all effects and persons she's an ordinary girl who happens to exist electronically."

"Are you sure this isn't just a dating sim?" asked Xenovia. "Who would have thought that Karasuma-sama played such things?"

"How rude!" protested Ritsu sharply.

Issei shook his head. "No, Xenovia, that is certainly a real girl."

"Are you sure?"

"Those breasts do not lie."

On the screen Ritsu went red and turned her back. Koneko put more force into the second elbow against Issei's side.

Karasuma put the phone - and Ritsu - away. "In any case, I've reported the situation so my superior."

"Excuse me, what is the situation?" asked Kiba Yuuto, coming down the stairs along with Shinra Tsubaki. Rias' knight and Sona's Queen had been seen together several times over the last few weeks of term, which even Issei thought was a good thing - even if it was possible Kiba hadn't quite grasped the reasons himself.

"Well Karasuma-san and his suite and Rias' cousin Karma and his peerage arrived and..." Issei frowned. "Actually I'm not sure about the rest of the situation."

"Karma's here?" Tsubaki winced.

"You know him?"

"Yes... although this is the first I've heard of him having a peerage."

Karasuma nodded. "It's a recent development."

"I suppose it would have to be. It might not be for the best that he's here. Leviathan-sama considers him a bad influence on the President."

"I'm the President," protested Xenovia. "Sitri Sona is the former President."

"She will always be President to me."

The bleuette swordswoman conceded that point. "So how did you come to meet one of the Gremory clan, Karasuma-sama?"

The angel folded his arms. "I've been Physical Education instructor for his class."

"Why would the Smiling Malakim be teaching Physical Education at a middle school?"

"That's classified."

Serafall burst into the hall at the top of the stairs and vaulted over Kiba and Tsubaki, transforming her costume in mid-air. "Issei-kun, have you seen her? Where is she?"

Tsubaki cleared her throat. "Ah, Leviathan-sama. Sona is..."

"Not Sona. The little cutie with blue hair."

"Ah! Third door on the left." Issei pointed.

An instant later that door burst open and three smallest members of Class 3-E burst out, red-faced and stammering. One of them, with green-dyed hair still growing out, had the presence of mind to close the door behind them.

"Is something the matter?" asked Karasuma.

"Ah -"

"Uh-"

"Ore - um," Shiota Nagisa looked around and realised they were the centre of attention. "Karasuma-sensei, what happened? Where are we?"

"Karma's cousin lives here. Karma and I brought you here for safety after the coach was blown up." Karasuma turned to Serafall, Tsubaki and Rias' peerage. "Allow me to introduce my students: Shiota Nagisa, Okuda Manami and -"

"Haruna Mase!" squealed Serafall. "Ooh! Are we on TV!? Is this a drama!? I loved your last show!"

"Actually, she's part of Karma's peerage now," the angel added drily. "They all are."

"...what's a peerage?" asked Okuda timidly.

"Perhaps I should explain this," Tsubaki suggested. "Meaning no disrespect, Karasuma-san, I have rather more experience with the Evil Piece system."

"The 'Evil Piece system'? asked Kayano warily. "That sounds..."

"Ominous?" Xenovia smiled reassuringly but Kayano looked at the devil's chest and then backed up with a pout.

"It's going to be okay, Kayano," Nagisa assured her. "We're alive and we're not even hurt."

Okuda clutched her hands together, "I-I-I saw..."

"All of your class are alive." Tsubaki held up her finger illustratively. "However, you're no longer humans. You see, the explosion you mentioned killed all but two people on the bus: Karasuma-san and Karma Gremory."

"But we're alive!"

"Yes, perhaps more specifically you were... what was that phrase."

"Mostly dead?" suggested Xenovia.

"Yes, that's what I was thinking." The spectacled devil turned back to the three junior high school graduates on the other couch. "Or if you prefer, you were dying. Karasuma-san and Karma-san survived because neither of them was human and they saved you by changing you so that nor were you."

"What do you mean, not human?" asked Nagisa.

Okuda held her hand up as if in class. "Er, do you mean like... Koro-sensei?" she asked and looked nervously at Karasuma.

He shook his head and stood. White wings spread from his back, stretching out past those on the couch. "My apologies, Okuda. I am an angel, sent to Kunugigaoka Junior High School to oversee the efforts to assassinate him. Karma is my counterpart, representing the devils."

"You're an angel?" Kayano squinted at him. "Well, I guess the wings prove it."

"But does that mean Karma's a bad person?"

Kayano and Nagisa's jaws dropped slightly as they looked at their classmate.

"Karma's a horrible person," Serafall asserted firmly. "But that's nothing to do with his being a devil."

"Angels are not perfectly good." Karasuma retracted his wings. "We try, but... well. Devils, like angels and like humans for that matter, have free will. Now that you've a devil yourself, Okuda, you'll be no more inclined to being evil than you were before. The same is true of Karma."

Tsubaki adjusted her glasses. "Thank you, Karasuma-san. Devils are creatures of desire, not of evil. The Great War between the Devils, the Angels and the Fallen Angels killed many of all three factions. Both the Devils and the Angels have devised methods to replenish their numbers by reincarnating selected humans as Devils - using Evil Pieces - and Angels - using Brave Saint cards."

"What about Fallen Angels?" asked Nagisa.

"Not so far as we're aware. Their leader, Azazel, doesn't seem to be interested in doing so." Tsubaki gave a little sigh. "Really, who knows that that man is going to do? In any case, humans can be reincarnated while they're alive or reasonably soon after their death." She smiled. "You must have all made a very strong impression on Karasuma and Karma that they felt they should reincarnate all of you. I'm sure you'll be grand angels and devils."

"But who would have blown up the coach?"

"I'm not sure," Karasuma told Okuda. "Now that Korosensei is dead I didn't expect that you'd be targeted."

Kayano nodded sharply. "I bet it was Chairman Asano." The actress gave Serafall a cautious look and edged a little further away from her. "If we were all dead he could lose our rankings and pretend that Class 3-A took all the top slots."

"O-or Shiro-san," suggested Okuda.

"I suppose he's capable of that but I'm not sure why he'd do that."

Kiba shook his head. "You seem surprisingly at ease with learning of devils."

"Ah... no one is going to be surprised that Karma is a devil," admitted Nagisa. "He's... uh..."

Tsubaki covered her mouth and giggled. "Yes, that's true."

"But if angels and devils knew Korosensei might destroy the world then why were only you and Karma sent to the class?" Kayano asked Karasuma.

"Destroy the world!" exclaimed Issei. "You're not serious?"

The angel looked over at Serafall who smiled. "Magical girls should be proud of their accomplishments, shouldn't they?" she asked rhetorically. "Tell us all about it."

"Hmm." Karasuma fixed each of the young devils in turn with a steely gaze. "This isn't to be widely discussed," he decided. "I don't expect you to keep this from your Kings but otherwise this is to be in the strictest confidence."

They nodded and Xenovia even crossed herself, wincing as she did so.

"Last year, at the end of March two things happened to our class," Kayano told them. "Firstly, most of the moon blew up." She smiled. "You probably noticed."

"I think everyone did!"

"And we got a new homeroom teacher." She lowered the tone of her voice and when she continued, the other two students and Karasuma visibly twitched. "'Nice to meet you,'" Kayano declared in a voice that suggested a grown man not a small girl. "'I'm the one who blew up the Moon. I'm planning to blow up the Earth too. In the meantime I'm your teacher so let's get along.'" She paused and rubbed her throat. "I'm out of practise," she said more normally. "Anyway, Karasuma-san was there."

"The exact story was a little more complicated than we knew at the time." Karasuma gave them meaningful looks. "However, unless he was assassinated, then the Earth would have been destroyed almost a week ago. Various attempts had been made by governments and by both devils and angels only to fail. He was simply too fast. Barring indiscriminate levels of force which might leave him destroying the Earth by accident, the only solution was get someone close to him."

"How could a teacher destroy the world?" asked Xenovia.

"Ask Azazel," replied the angel and the Knight winced.

"He wanted to be our teacher so the government agreed and sent Karasuma-san to teach us to be assassins."

"And you succeeded. Brilliantly. I'm certain he was proud of you."

"Proud, but...?"

"He said: 'We want an assassination worth smiling about - one to be proud of.'" Nagisa said softly. "Excuse me, is there a bathroom?"

"Sure." Issei pointed.

"Thank you." The bleuette didn't hurry but the tension as Nagisa left in the indicated direction was visible.

"She's a sensitive girl," said Issei seriously. "Maybe she'd get along with Asia, do you think, Kiba?"

Okuda and Kayano exchanged looks. "Nagisa-kun is a boy, Hyodo-san," Kayano corrected him.

"KARMA IS A BITCH!"

Serafall's scream knocked everyone but Karasuma off their feet. Okuda rolled into a ball and black, bat-like wings popped out of her back, folding defensively around her.

The Maou paused and coughed into her fist. "I'm sorry, that was out of order," she added politely and then took Nagisa's former seat between Kayano and Okuda. "Tell me, how do you two feel about magical girls?"

Ajuka Beelzebub listened to Karma's explanation and then shook his head. "There are good reasons I permit only high-class Devils to establish a peerage. I see you don't regret the deed but you may regret the consequences."

"Sirzechs owes me."

"You don't imagine he'll spare you the punishment for this transgression? Neither Serafall nor myself would support that."

Karma grinned cheekily. "He can approve me to take the test for promotion though. Only one of the four Maou is required for that."

"I see you're overconfident as usual." Ajuka shook his head. "Nor will that be the only issue, however you can face them on your own. Be aware though, Karma Gremory. Passing the test when two Maou disapprove won't be as easy as you imagine."

"I usually test well." The younger devil clenched his fists inside his trouser pockets. "Score me fairly and it'll be easier than most of the tests I've taken this year."

Ajuka arched an eyebrow. "You'll rise or fall by your own merits in my eyes. I make no such promise for Serafall - or for Grayfia."

A/N: The crossover is High School DxD / Assassination Classroom