"Deku." Normal Speech.

'Deku.' Normal Thought.

"Smash!" Power/Technique.

"One for All!" Demonic/Dragon Speeches.

'One for All!' Demonic/Dragon Thoughts.

Summary: The day he was supposed to start training his One fall All with All Might, Izuku saved a boy from getting killed by his girlfriend and got himself hurt in the process. Though it gave him new friends, the instinctive act of heroism also got his three high school years of prepping for Yuuei University tangled up in the mess that was the world of devils, angels and fallen angels…

Izuku x Harem

Some basic world building for this story just in case anyone misses or misunderstands the information I am going to try to cover with this chapter. There are some changes to fit the merged world of DxD and MHA.

Quirks and Sacred Gears exist naturally together in this AU universe of My Hero Academia and High School DxD crossover. Sacred Gear users are rare just like DxD canon. There are those with Quirks but do not have Sacred Gears, and likewise there are also those who have Sacred Gears but do not have Quirk. Those who possess both Quirks and Sacred Gears are extremely rare cases, however.

Actual supernatural beings, like pureblooded devils, angels, and fallen angels… does not possess Quirk.

Yuuei Academy is a university. Kuoh Academy IS NOT a hero school. It is simply a normal academy with the Escalator system that offers fundamental hero class to prepare a number of students who wish to pursuit a hero career for Hero universities, including Yuuei, which in this AU universe of this story, is the starting point for those who want to become pro heroes (not from high school like canon MHA).

This will be a story of an Izuku learning OFA under the guidance of All Might, whose attention for his successor will not be distracted by his role as a teacher like in canon.

The Highschool Hero

Chapter 1

"It has been almost a day already, but… why do I still not feel anything different?"

Izuku Midoriya thought to himself while looking at the palm of his hand.

One for All.

It was the name of the Quirk of All Might, the Symbol of Peace and the current number one pro hero. It was, in short, the power that could be passed down from person to person in the manner, on the words of All might himself, not unlike the sacred torch of legend itself, granting the one currently wielding it what seemingly appeared to be a generic huge boost of strength, but All Might stated that it was actually the cultivated strength of all predecessors of the Quirk, and there was a lot more to One for All than just the unbelievable abilities that he had shown.

And the day before, it had become his Quirk.

Having deemed and chosen Izuku to be a worthy successor to inherit Quirk, All Might had pushed him through ten months of hellish physical training to prepare his body to hold the raw power of One for All, or else he would be blown to bits. It would be a huge understatement to say that it had been incredibly difficult ten months for Izuku, who barely had the strength to keep himself awake outside of training at first.

However, in order to fulfill his dream and become a pro hero who could save everyone, he had managed to finish the challenge All Might had given him just in time, physically becoming the genuine vessel that the man had wanted.

Yesterday, he had ingested a strand of hair of his idol, which was apparently the method of transferring the Quirk. In all honesty, as he attended his high school for the first day earlier that day, Izuku had been incredibly worried that his limbs would fly off like what his idol had warned him, but since he was still in one piece, the training appeared to have paid off.

But for some reason, Izuku could not help but feel that there were still no significant differences.

And speaking of high school, yesterday, he had officially become a first year high school student at Kuoh Academy, one of the most renowned schools for those who wished to sign up for Yuuei University, which boasted the best heroic education in Japan. The academy was originally a normal all-girl school, but had recently become co-ed and opened its own basic fundamental hero training classes, which were actually sponsored by Yuuei themselves, for those who wished to have a hero career with how much it had grown as a profession.

For someone who wished to attend Yuuei to become a pro hero like him, Kuoh was the best high school he could ever hope for…

… even if he had to attend the same class as his childhood friend, Katsuki Bakugo, for another three years, which was by no means a bad thing to Izuku since he was worried that he could not make any new friends in high school any time soon.

"I need to hurry up. All Might-san has probably already arrived."

Izuku spoke to himself and started picking up the pace of his running after checking the time with his phone, realizing that it was almost time for his first Quirk training with All Might. Even if he had three long years to train in One for All and prepare for Yuuei University, Izuku did not wish to waste even a second of it, especially when it was under the guidance of his idol, All Might himself.

But just as fate would have it, Izuku heard a scream coming from the local park he had just crossed...

"AAHHHHHH!"

Izuku's eyes widened in surprise and stopped running, pausing idly for a second before turning around on his heels and running toward the direction of the scream as fast as he could even before his mind could deduce what was going on. In less than ten seconds, the dark green haired young man made it to park, arriving at an area near a large fountain.

There, he found a young man who he could instantly recognize to be Issei Hyoudou trying to run away while holding his bloody arm, but tripped and fell over in panic before he could make it anywhere. He was a second year of Kuoh academy who was a member of the Perverted Trio, who were so infamously known for their perverted behaviors and their usages of their Quirks for such acts that Izuku learnt their name on his first day at Kuoh.

The one who was walking behind him with a surprisingly casual air about her, was a black haired young woman with a pair of black wings on her back, which Izuku instantly deduced to be a flight Quirk or something similar. Her outfit consisted of black leather that encircled around and under her breasts, a thong-like piece held around her hips by three thin straps, gloves that ran right up her arms with small lengths of chains hanging from them, and a pair of black thigh-high heel boots, giving her the impression of a dominatrix.

But not that Izuku cared, because holding in her right hand was a long object that looked like a long spear made of light, and it was dripping with the same blood that was flowing from Issei Hyoudou's bloody arm.

"No, stop!" Izuku cried out and removed his backpack to throw it at the winged young woman, causing her to widen her eyes in surprise as she turned her head to look at him before jumping back to dodge, using her wings to float in the air, flying just as Izuku had anticipated. "Get away from him!"

"Ah, and who are you? How did you…" The black winged young woman asked in surprise, as Izuku got in front of Issei and stood protectively in front of him, even though his body was shaking and sweating profusely in fear and nervousness, which the one he was facing instantly took notice "Trying to play pro hero, aren't you?"

"I am not… but I won't… let… you hurt him." Izuku stated while trying his best to show a brave front, holding up his hands and taking a basic martial art stance that he had seen a pro hero assuming in the past.

"Look how much you are shaking. You can barely hold up your hands. Sorry kiddo, but I do not have time to play the game with you. I gotta finish this quick before an actual hero catches wind of this and shows up." The black winged woman said as she twirled her light spear around and shot at him with her wings, making Izuku jerk back in shock at the speed that she was flying. "You are not my target, so I will let you live if you just step out of my way."

There was no way he could do that.

"Watch out!"

Issei Hyoudou cried out, but his vision was blurring from losing so much blood. Even though he could not see the face of the boy trying to protect him, he could see his shoulders shaking in fear as he continued to stand tall on his feet, refusing to move even as the winged woman continued to come at them then with the intent to kill.

'I… I cannot just die here…' Izuku thought as he brought his fist back, his foot stomping into the ground as the young man braced himself. 'Not like this… I gotta protect him.'

It was at that moment, that the words All Might had given him soon after eating his hair to inherit One for All played in his mind.

"From now on, young Midoriya. Whenever you throw your punch…"

"GAHHH!"

Izuku screamed, as red veins spread across his right arm and both of his legs, causing the ground beneath him to crack before exploding as he threw his punch while crying out.

"Remember to clench your butt super tight, and scream out this word from the bottom of your heart."

"SMASH!"

THE HIGHSCHOOL HERO

"See you tomorrow, Nejire-chan. I gotta go to my club now."

"Oh, of course. Don't let me hold you back, Rias-chan! See you tomorrow!"

Rias beamed while waving her hand at her classmate and good friend, who went by the name Nejire Hado, as they left the teacher office together, having had a meeting with their homeroom teacher and a number of others in there to discuss the upcoming events.

At the same time, the students who were members of their fan clubs, squealed and cooed at their interactions while standing in the hallways and crowding over the two, making Rias sigh inwardly as she proceeded to leave the new school building while Nejire left in the opposite direction.

Then again, she could not really blame them for having such reactions whenever they found her and Nejire working together, for they were two of the top three most beautiful girls of Kuoh academy, with their beauties being matched only by their talents.

Top of fundamental hero classes with an exceptionally powerful Quirk, Nejire was a fair-skinned, beautiful young woman of average height with wide, curious eyes of royal blue. Her hair was periwinkle, and it reached all the way down to her knees, twisting around itself at her waist and curving inwards around her legs, with side-swept bangs tucked behind her ears on the right and hanging just over her eyes on the left, and two short clumps of hair on either side of her face, curved towards her face on the right and behind it, under her ear, on the left.

Rias, meanwhile, was an incredibly beautiful young woman with blue-green eyes and long, flowing crimson hair that covered her back like a curtain of silk. While Nejire was acknowledged by the boys of Kuoh academy as well as the local school to be 'the cute kind' of girl, Rias was without a doubt the sexy one between them, as her hourglass body surpassed even that of the top class supermodels, with the most noticeable feature being her exceptionally large bust.

Unlike Nejire, however, Rias did not participate in the hero classes that Kuoh offered for those who wished to pursue a pro hero career despite being acknowledged by most if not all of Kuoh, including even the teacher themselves, to have a ridiculously powerful Quirk, Destruction. Many found this to be strange, but Rias simply wanted to have a normal high school life and preferred to use her Quirk for self-defense only.

And little did they know that her 'Quirk' was not a Quirk at all. Calling her power a Quirk was simply a way for her to blend in comfortably.

"Good afternoon, everyone!" Rias beamed upon reaching her clubroom in the old school building of Kuoh academy, where she was the president of the Occult Research Club, which was a cover front for who she and the members of her club were.

"Good afternoon, Buchou." greeted a petite girl with white hair and gold eyes, who sat on the Victorian styled couch in the center of the room munching on a slice of cake. Like Rias, she was dressed in the school uniform for girls of Kuoh academy, albeit the shoulder cape.

"Afternoon to you as well, Koneko."

Rias smiled at the girl, who was deemed the mascot of Kuoh academy thanks to her overwhelmingly cuteness. The tone that Koneko had used to greet her was one without most emotions, but Rias had gotten used to it by then.

"Ara, welcome, Buchou." Akeno Himejima, her best friend and the vice president of the Occult Research Club, said as she approached Rias with a gentle, but somewhat amused smile on her face, making the crimson haired young woman beam back in response.

Being one of the most beautiful girls of Kuoh academy alongside her and Nejire, Akeno was an incredibly beautiful and attractive young woman, with long black hair that was tied into a long pony-tail at the back of her head by a large orange ribbon. Like Rias and Koneko, she wore the customary Kuoh Academy girls' school uniform, along with black calf-length socks.

"Hey, Akeno." Rias smiled at her best friend, as she took off her bag and left it on the couch before taking a seat there, smiling as Akeno stepped forward and poured her a cup of her handmade green tea. "Thank you, Akeno. Where is Yuuto, by the way?"

"Oh, he has a class meeting, so he will not be able to come until later today." Akeno answered, making Rias nod her head in understanding while blowing lightly on her tea to cool it down and drink "How was your meeting with the teacher earlier? Did Takeyama-sensei try to persuade you into joining Yuuei next year again?"

"Oh, she did. And like last time, I politely turned down her proposal." Rias answered with a shrug of her shoulders, making Akeno giggle amusedly in response "And the meeting went well. I think the upcoming festival is gonna be the best one that we have yet with all the plans the teacher and Sona have been making."

"I cannot wait. Are we going to participate as well?"

"Of course. It is going to be a great competition, one that I intend to win again." Rias declared confidently, with a crimson aura surrounding her body.

"My, with an attitude like that, no wonder why the teachers want you in Yuuei. You will make a good hero."

"Me? A hero? Pfft." Rias chuckled sarcastically while making a noise with her lips. "Speaking of, I think there are some potential…"

Before Rias could finish, the glowing circle on the floor of her clubroom suddenly lighted up, emitting a radiant crimson light that made all three girls in the room turn their heads to look at, understanding that someone was not just summoning one of them, but they also had a desire strong enough to summon Rias herself, their leader.

"Well, I guess my shift starts earlier than usual today." Rias said as she put her empty cup down to stand up, making her way over to the circle on the other side of the room.

"Do you want us to come with you, Rias?" Akeno asked, "Remember last time?"

"I do. But I have a feeling that it is not going to be a villain again. Plus, the servants of my house have fixed the summoning spell, those with certain malicious intents will not be able to summon us anymore." Rias explained before stepping onto the circle, and activated it with a wave of her hand "I will see you two later."

"Understood, Buchou."

With that smile from Akeno, the magic circle under her feet shone brightly before teleporting her away, making Rias disappear from the clubroom.

To the crimson haired young woman, however, her surroundings simply shifted and changed. Her eyes then widened in surprise, however, when she saw Issei Hyoudou staring up at her with eyes as wide as dinner plates while holding his bleeding left arm and sitting with his back leaning against the trunk of a tree. There was a bewildered look on his face, and Rias could not help but have a feeling that it was not for her sudden appearance.

"Issei Hyoudou-kun, are you…" Rias questioned in concern as she lowered herself down to check if Issei was hurt anywhere else.

He was, after all, a potential candidate that she wished to have as a member of her peerage, as not only did he have a strong Quirk, which he unfortunately only normally used for perverted purposes, but he also had an incredibly power resided within him, making him an incredibly special individual with vast potential for greatness.

Her question was cut short, when she saw Issei turning his eyes to the side. Curious, she turned her head around to see what he was looking at, and the scene caused her jaw to drop in shock.

Utter destruction, there was no other way to put it. If Rias did not know any better, then she would think that the area had been hit by a storm or a tornado, because the ground looked like it had been blown up by a powerful gust of winds, while the trees around it looked ready to collapse, with several branches hanging them and falling randomly onto the ground.

What shocked her the most, however, was the two figures lying in the destroyed area, one them being Yuuma Amano, or Raynare, as she lied barely conscious with her back leaning against the destroyed fountain, a horror look on her face as her body was soaked in her own blood, looking like several bones in her body had been broken, including her wings as they hung limply at her side.

The other figure, meanwhile, was that of a first year boy she had caught a glimpse of at the opening ceremony for the first year student yesterday at Kuoh academy, with short but fluffy dark-green hair which stuck out around his head. The boy appeared to be unconscious, lying facedown on the ground with one arm stretching outwards in front of him.

What shocked Rias the most, however, was the fact that that arm of his and both of his legs were twisted in odd angles, and it did not take it long for Rias to realize that all of his bones in those limbs had been completely shattered.

"He… he saved me." Issei suddenly spoke up, causing Rias to turn her head to look at him.

"What do you mean, Issei Hyoudou-kun?" Rias asked hurriedly, trying to grab the basic idea of what had happened in order to know that she was not going to help someone who did not deserve it.

"He… he defeated Yuuma-chan." Issei swallowed heavily and said "She… tried to kill me, but… he saved me."

"I see." Rias nodded her head in understanding, before bringing out her phone from her pocket to call Akeno "Can you be fine here on your own, Issei? Your arm is bleeding." The brown haired boy nodded his head in response, and it was then that Rias rose up to her feet and rushed over to check on the other boy, who seemed to have passed outt due to the immense pain he was feeling.

As she called Akeno while using a quick spell to stabilize his condition somewhat, she could not help but look between the screen before her and the boy lying on the ground with his arm and legs completely broken, wondering if he was the one who had caused so much destruction with his Quirk.

And if it was, then what was it to have made his body suffer so much damage, given that it was not caused by that Fallen angel, Raynare.

End of chapter 1

Note: And that is the end of this first chapter for this story! WOOO! A new story everyone!

Another DxD crossover from me, this time is with My hero Academia! I have no idea that everyone will like it or not, and this is only the first chapter, but I want to at least give it a try, since I have been getting into MHA a lot recently. Maybe it will do well, maybe it will not… but as always, I hope that everyone will still have a good time reading and enjoy my writing as usual.

So yes, this is the first chapter of The Highschool Hero. I hope that everyone likes the basic world building for this story that I have made. We will go further into it in the chapter to avoid major spoilers, but for the time being, it is what I have stated. The story will take place at Kuoh academy, while Yuuei Academy has become a university. This will give Izuku 3 whole year to train in OFA to prepare for Yuuei unlike canon, with an All Might who is not restricted to teaching him solely because he cannot play favorite as a teacher.

All events of DxD and MHA will be mixed into each other, and I will build stories around it to make sure that they make sense as much as possible. For example, it makes sense for Rias to blend in by saying that her demonic power is a Quirk, allowing her to actively and publicly use her power without raising questions like in canon DxD.

Because of this, class 1A of canon MHA does not exist (just yet) in this story, because Kuoh work fundamentally as a normal school with classes for those who want to pursuit pro hero career, so not all needed to join Kuoh. I do, however, wish to include some of my favorite class 1A's characters into this story already and become friends with Izuku in this story, tagging along with him in his adventures in the world of supernatural beings. They might or might not attend the same class as he does, but they will still be a student at Kuoh Academy.

So far, I have decided that Ochako and Bakugo will be two of his classmates. As you can also see, Nejire is a third year in this story while Yu Takeyama, Mt. lady, is a teacher at Kuoh (she will be teaching hero classes sponsored by Yuuei), both of whom I really like so I decide to include them in this story. Momo will also be a student of Kuoh academy, but to make it feel more… natural like a normal school it is supposed to be here, she will be in a different class as Izuku, Ochako and Bakugo.

Who else that can be added? I am thinking Shouto can be one, since I have established that Kuoh is the best stepping point for students who wish to pursuit a hero career when they go to college, so it will be natural for him to attend Kuoh as a student and interact with Izuku and the 'MHA hero' classmates. If you want to see any other characters from canon MHA, feel free to suggest them in the comment section. I will make sure to consider each option and add them to the story as a classmate or friend of Izuku (but not all of canon class 1A though, since I do not want the story to all too clustered up with characters from both series).

That will be all for now. If there are anything too confusing, then feel free to DM me to ask about them and I will be sure to answer all your questions. As much as I want to go in depth to explain the world I have built for this story, it will be like spoiling future chapters and it will make the story/chapters boring to read. So please patient, okay? All of your questions will be answered in due time.

Oh another thing, while Izuku is seemingly saved by Rias here in this first chapter, which is a typical setting for the protagonist of this crossover section, I will not have him turned into a reincarnated devil. Hope that this is acceptable as well

I am also thinking about giving him a Sacred Gear for even more diversities in fighting, but have not found anything that go well with OFA yet. Any suggestion as well?

That will be all! Once again, I hope you have enjoyed reading this chapter and will come to love this story. As always, make sure to leave me a REVIEW once you have finished reading. Show me a lot of love if you can and I will deliver the next chapter as soon as possible!

Check out my p/atreon if you can for early access to my works, as well as if you wish to make commissions! Feel free to join my discord channel as well and be a part of my community (the links to both can be found in my profile)

See you in the next chapter!