A/N- So, I kind of wanted to write a Rosario + Vampire fanfic, and I thought it would make for a good xover with DxD. This is the result. The Rosario side of this story follows the events of the manga. Tsukune won't be the only character to appear from Rosario, but he will be the main one.

I don't know how much I'll do with this, it all depends on the response, so be sure to leave a review.

Disclaimer- I OWN NOTHING!

(-)

The incessant ringing of the alarm informed Tsukuna Aono that it was time for him to wake up. His hand slammed down on the button in aggravation, but he got up none the less. Letting out a yawn as he stretched his limbs, he began his routine morning ritual. Shower, get dressed, breakfast, collect his things, and then head to school. He went through the process with an almost robotic efficiency, not wasting any movements on unnecessary actions. It was only natural given how many times he did it, having long since become accustomed to the monotony. But he took pleasure in the predictable. After the craziness that was his teenage years, he had looked forward to a more organized adulthood.

Exiting the apartment that he was renting, he looked up to the bright blue sky with a smile. "Today's gonna be a good day." he said before turning to lock the door. All that was left was for him to head to his destination, the gathering place of the youths who seek knowledge. Or, in simpler terms, high school.

However Tsukune was not going there as a student. No, for the past few months he was the second year math teacher at Kuoh Academy. A rather prestigious and well known school that up until this year had been an all girls school. However that had changed and now boys were allowed to enroll. But the majority of the student body was still comprised of girls.

As for why Tsukune was a teacher there, per the instructions of the late headmaster of Yokai Academy, before he could officially take over the position of headmaster himself, he had to complete several years of teaching. And it was noted in the previous headmasters will, that a good school for him to teach at was Kuoh Academy. So, seeing as how Mikogami was always the man with the plan, Tsukune found himself going along with the recommendation.

The school was only a short walk from his apartment, so Tsukune didn't find it necessary to take the bus. Rather, he enjoyed being able to take in the sights and get some exercise from his walk. As he neared the school, he heard his phone go off. Pulling it out he flipped it open to see who it was. There was a text message that read 'We all miss you! Hope you have a good day!'. Attached was a photo of the 5 most important girls in his life. Mizore, Kurumu, Ruby, Yukari, and of course Moka. They were all smiling and waving at him in the photo. It was times like this that Tsukune felt his happiest. Knowing that he had 5 loving women waiting for him to return. Closing his phone, Tsukune looked down at his finger and the ring that adorned it. A fond smile made its way across his face before he continued on his way.

Upon arriving at school, Tsukune witnessed a rather common sight. Three male students, who were aptly nicknamed 'the perverted trio' were being chased across the grounds by the girls kendo team who were brandishing wooden swords and swinging them violently in their direction. Tsukune could only sigh in exasperation at the antics of his students. Issei, Matsuda, and Motohama were three students who seemed to let their libido guide every action they made. It was no surprise that they were the enemy of all woman-kind.

As soon as the trio spotted Tsukune, they made a b-line for him and cowered behind him.

"Help us sensei!" the trio cried.

Meanwhile the girls had caught up and Tsukune put himself between the two groups.

"Hand them over sensei!"

"They must be punished!"

Tsukune let out a wry chuckle. "What did they do this time?"

"They peeped on us in the changing room again!"

Tsukune turned to the boys and glared slightly. "Is this true?"

"We were only doing what any normal male teenager would do!" shouted Issei.

"That's right! It's a completely normal occurrence. They should be used to it by now." added Matsuda.

"No one should have to be used to having a bunch of peeping toms!"

"Yeah! Now let us mete out justice on these scum, sensei!"

Tsukune smiled warmly, it was a smile that could melt the heart of any woman he came across. "Now girls, don't you think that's a bit unbecoming of such gorgeous students? Resorting to violence so quickly will make it hard for you to find a partner in life."

The girls swooned at Tsukune's words. As the years went by, Tsukune's appearance had changed a bit and as a result he was regarded as the 'handsome stud teacher' at Kuoh. That being said, the girls had a hard time going against his words as most found him attractive. This also made students such as the perverted trio dislike him, but that was offset by his kind nature in helping them avoid the more painful punishments courtesy of the girls.

"I will ensure these three are properly punished for their transgressions, so why don't you head back to your club. I'll be sure to stop by later and sit in on your training and give you some pointers." Tsukune added.

The girls begrudgingly relented and left, causing the perverted trio to sigh in relief. However they began to sweat nervously when Tsukune turned around and glared at them.

"Uhh... thank you sensei." spoke Motohama.

"We'll... be on our way now." said Issei as the three turned to leave.

"Not so fast." Tsukune said as he grabbed the three by their collars. "You still have to pay for your crimes. I expect all three of you to meet me after school today. Are we clear?" Tsukune said in a tone that left no room for negotiation.

"Yes sensei." the three responded.

"Good. Now get to class." Tsukune said as he released his captives. 'Hmm, I wonder what I should have them do today.'

Tsukune found that the trio cared not if they were suspended from school, so he had to devise different forms of punishment for them, such as doing community service and the like. Either way, the trio preferred that as opposed to getting beaten. Looking down at his watch, Tsukune saw that if he dawdled any longer he would be late for class.

(-)

Tsukune sat at his desk in the teachers lounge, going over the results of the tests that he had his students take. They were good for the most part, save for a few exceptions. The perverted trio in particular. From what Tsukune was able to learn, the trio only studied hard enough to get accepted to Kuoh academy, since it had just recently become coed. Apparently, they figured that there would be plenty of girls for them to prey on.

"Hahh, I really need to do something about those knuckleheads."

"Deep in thought Aono?" came a voice.

Tsukune turned to see one of his fellow teachers. Aikuro Mikisugi. He was a shaggy looking individual who had a faint beard, messy blue hair, and always wore sunglasses.

"Is it that obvious?" Tsukune asked.

"We've known each other a while. I can tell when something's on your mind." answered Mikisugi. "That and you've got your papers upside down."

Tsukune looked back at the tests and saw that he did indeed have them upside down. "I guess that makes it obvious."

"Let me guess, the perverted trio again?"

"Got it in one." Tsukune confirmed. "Yep. Those three were caught peeking on the girls kendo club again. Now I have to come up with an extracurricular punishment for them this afternoon." Tsukune said as he leaned back with his hands behind his head.

"Hmm, perhaps polishing the gym floor?"

"No. They did that two weeks ago. I want something fresh. I'll probably have them volunteer at the soup kitchen or something." Tsukune then let out a heavy sigh. "Man, I'm just too concerned about their futures, aren't I?"

"It's the job of a teacher to look out for the well being of their students." said Mikisugi.

"If they don't change their ways, then they'll end up ostracized in society and won't fit in anywhere." explained Tsukune. "Do you know what Issei's dream is? He wants to be the harem king." Tsukune laughed wryly. "He wants a harem in this day and age. Ridiculous." Tsukune knew he was being hypocritical, what with having his own harem and all, but he was an exception. He was no longer bound by human convention. That all ended when he took off the Holy Lock and truly became a vampire.

"Well, to each his own." mused Mikisugi. "I guess he'll just have to learn the hard way that his dream is unrealistic."

"Somehow I don't think that will make him give up on it though." Tsukune said dryly.

"By the way, I've been meaning to ask you."

"Hmm?" Tsukune grunted as he turned his head to Mikisugi.

"You never said who the lucky lady is." Mikisugi said, pointing at Tsukune's hand, more specifically his finger.

Tsukune raised his hand up towards the light and gazed at the ring. "You're right. I didn't."

"Heh, see you later Aono." Mikisugi said with a wave as he left.

(-)

The next day went about the same as the last. Morning routine, head to school, perverted trio, rinse and repeat. However on this day, when he said he was going to punish the trio, Issei objected.

"I can't stay after school today!" the teen cried. "I have a date with Yuuma-chan!"

"Yuuma-chan?" Tsukune said questioningly.

"This asshole got himself a girlfriend." grumbled Matsuda.

"And he won't stop rubbing it in our faces." added Motohama.

"Yeah! I'm taking her out for our first date this evening!" Issei then got on his hands and knees and begged. "Please sensei! Please let me off the hook! Just this once!"

Tsukune scratched the back of his head, feeling something akin to pity for the pervert. This may be his only chance at romance, and Tsukune didn't want to screw it up for him. "... Fine. I'll let you guys off the hook. Just this once."

"Yes!" the three cheered before heading to class.

"... I should probably follow him and his date in case he does something unbecoming." Tsukune mused.

(-)

It was after school and Tsukune was covertly tailing Issei who was heading to meet his girlfriend. The teen was standing around what Tsukune figured was their meeting point, but it seemed that in all his nervousness, Issei had arrived quite early. It was still another twenty minutes before Yuuma showed up.

What followed surprised Tsukune. The date had gone rather well. It was just your average teenage date, but Issei was pulling out all the stops and acted like a proper gentlmen. But regardless of how well it was going, or whether or not he was totally invading his students privacy, Tsukune continued to tail the duo. Even as they headed into the dark park.

(-)

"Hey Issei?" Yuuma called out as she led Issei towards the center of the park.

"What's up Yuuma-chan?"

"Can I ask something of you?" she asked with a blush on her face.

'Here it comes! First date, twilit park... the perfect spot for a first kiss!' Issei's heart was practically beating out of his chest. "Wh-what'd you want to ask me?"

Yuuma spun on her heel and smiled. "I was wondering if you'd die for me?"

"Huh?" Issei uttered. "I'm sorry, can you repeat that? I think I had something crazy in my ear."

"I was wondering... if you'd die for me." Yuuma repeated, this time darkly.

"W-what?"

Suddenly Yuuma's clothes tore away in a flash of light. Her figure filled out, black wings sprouted from her body, and a skimpy black leather getup formed over her body.

Issei hardly had any time to take in the sight of Yuuma's exposed body before the gravity of the situation settled in. Yuuma was a monster!

"The date we had together was fun." Yuuma said as she lifted up off the ground. "Even if it was a bit childish." a spear of light formed in her hand. "Now die for me~."

Issei's feet were rooted to the ground in fear, even as Yuuma hurled the spear towards him. But just before it skewered him, someone intervened.

Issei felt himself being tackled from the side and rolled out of the way of the spear.

"Hnn? Who are you? I thought that we were alone." Yuuma spoke with a hint of irritation.

The man who saved Issei stood up and pulled off his tie. "The name's Tsukune Aono. And I won't allow you to harm one of my students." he said as he glared at Yuuma.