Japan may seem like a free country and an example of resilience, but what it hides is a society obsessed with work, high housing prices, and gadgets for survival, making the poor people of its society live a difficult life that is not much different from what people experience in third-world countries.

Among these inhabitants of the Land of the Rising Sun is Iruma Suzuki, a 15-year-old orphan who has understood from an early age that life is tough. His story begins like any orphan's, but Iruma's has a unique twist. He was found by an old, poor woman who lived in the mountains.

This kind-hearted lady took pity on the poor baby and raised him until he was five years old. Unfortunately, she passed away, leaving her meager property for the boy to live on. From that age, Iruma began working in various jobs - fisherman, bear hunter, game tester, manga assistant, traffic guard, and more. This left him with little time to attend school, but his education was not neglected thanks to books and the explanations given by the people who worked with Iruma, who sympathized with the harsh life the child had to endure.

Thus, between jobs, surviving in the wilderness, and studying, the path that guided the young boy led him to become a healthy and surprisingly strong teenager by the age of 15. He possessed incredible agility and a keen sense of danger, as well as an unusual affinity with the shadows of the world, causing him to have no fear of the night and death.

This lack of fear of the night and his heightened instincts presented Iruma with opportunities to take on nocturnal jobs that others would shy away from. He excelled at tasks like stealing money from the mafia or evading the police as a courier, although the latter did not sit well with him. However, he resorted to them when money was tight at the end of the month.

But lately, that didn't seem to be a problem, as Iruma had secured a job at a pizzeria where he was paid well, and the owners were kind enough to accommodate his work schedule with his schooling. He enjoyed this job, and it provided him with financial stability. It was common to see a young man with blue hair riding his bicycle through the streets of Kyoto, delivering pizza orders promptly. His speed, combined with his keen instincts, made it appear as if he were riding a horse and effortlessly navigating obstacles, earning him the nickname "Blue Kaze" due to his distinct and unusual blue hair, as well as his swift deliveries.

With the promise of a reward in mind, Iruma was now on a new route due to a new customer who had called just minutes before the pizzeria's closing time to order a classic Margherita pizza and a 3-liter cola. This customer lived in the mountains near Kyoto, a journey that would take an hour for any other delivery person and came with its share of fearsome challenges.

But for Iruma, not only did it not matter, but he was also quick, and with the advantage of his bicycle, he could make it in 30 minutes. With that in mind, the order was placed, and he was promised two slices of pizza and a free soda as a reward for his effort.

With the reward in mind, Iruma swiftly arrived at the residence in the mountains, a traditional Japanese house without public lighting due to its remote location far from the bustling city of Kyoto.

Without fear in his mind, Iruma got off his bicycle and parked it near the entrance. He took out the pizza and the drink in one hand and, with difficulty, as he struggled to hold two objects with one hand, he knocked on the door to alert the homeowner.

It didn't take many knocks for the door to open, revealing a beautiful woman with black hair. Iruma would have been stunned by her beauty if he didn't sense danger in her dead eyes, which had a strange black coloration, as if they belonged to insects.

"Wow, you guys are really fast, and your product looks delicious," said the woman in a sweet tone that would have captivated any man or even a woman. However, something in Iruma's instincts warned him that he was in danger.

"Here's the family-sized Margherita pizza and the 3-liter cola. That will be 2,000 yen, please. We accept any form of payment," Iruma said, doing his best to hide his discomfort.

"Oh, that sounds great, and I can't wait any longer to try it. You have no idea how hungry I was when I saw you zooming through the city at high speed, stirring up my appetite," said the strange woman, who showed only the back of her body as she licked her lips.

"But I don't have any money right now. How about you come inside and wait while I go get the money?" the woman suggested, opening the door to invite Iruma in.

"I don't like to be impolite, but due to store policies, I can't enter other people's homes. I have no problem waiting outside. I'm not afraid of the darkness or the night," Iruma replied politely while trying to conceal his nervousness.

"Such a shame. Well, it's never bad to have a meal in the open air, and even if this is just a few inches outside my territory."

The woman's words left Iruma puzzled, but his confusion ended when he saw something quick and sharp coming from the darkness towards him. With his incredible senses, Iruma managed to dodge the attack.

Before he could fully comprehend what had happened, the woman's body began to emerge from the house, but now her torso was several meters above the ground. A body that made no sound but was repugnant and large, with enormous legs, started to emerge from the house.

"I must say, I didn't expect you to dodge that. Most of my delicious prey can't even react to my attack or understand when I start devouring them. But unfortunately, you, my little one, are going to experience the full terror of the chase," said the woman cruelly, as she emerged from the house and looked at Iruma with amusement. Her words suggested that she found it fun to pursue challenging prey.

Iruma, without saying a word, tried to grab his bicycle and escape, but he quickly moved away from it when a spit of acid hit the bike, melting it completely.

Iruma looked at the woman, who was wiping the venom off her face and smiling at what she had done. With fear in his heart, Iruma began to run towards the forest, with the monstrous woman in pursuit.

As he ran, Iruma dodged the acid attacks that the woman launched, which melted the ground and trees. Adrenaline surged through his heart as he fled from the woman who destroyed everything in her path while laughing cruelly.

"Come on, it's useless. Surrender, and I promise to devour you quickly, but not before savoring a couple of your limbs and arms," the centipede-like woman said with malice as she continued to hurl acid at Iruma. As the forest terrain became increasingly challenging, Iruma found it harder to evade the attacks.

This proved costly when, while dodging one of these attacks, his foot did not land properly, causing him to stumble and fall down a hill in the forest until he collided with a tree. The impact caused one of his arms to dislocate.

"It seems my dinner has softened. This will enhance the flavor," the woman said, approaching Iruma with a look of hunger and sadistic glee.

"So this is how I'll die, huh? A crappy life ending like the crap in a monster's belly... I'm sorry, Granny, but in the end, I wasn't a great man," were Iruma's final thoughts as he futilely attempted to raise his hand to stop the woman centipede's charge.

"Argh!" However, what followed was not the sound of a boy being devoured but the scream of a monster in pain as it felt a significant portion of its body disappear under a beam of dark energy that emanated from Iruma's hand—a beam of light that Iruma did not see as he had his eyes closed.

Upon opening his eyes, Iruma saw the centipede-like woman struggling to recover from the attack she had endured and trying to regenerate the lost part of her body. Seeing that her regeneration as a monster was failing, the woman turned to Iruma with pure hatred in her eyes.

"I will make you suffer!" the centipede woman screamed, anger evident in her voice, as she once again approached the wounded Iruma. This time, he didn't close his eyes but instinctively raised a shield of energy around himself, and the woman collided with it forcefully, sending her flying backward.

Seeing that her second attack had failed and feeling the increasing pain from her wound, the centipede woman tried to crush the energy shield, but her incredible strength, which could crush a blue whale with a single squeeze, was having no effect on the shield that had appeared.

Iruma watched as the monster hurt herself in her futile attempts to break the shield, not understanding what was happening. However, when he looked at his hand, he could see a blue energy emanating from it without causing him harm. The energy made him feel good, like a summer breeze, and it calmed him. With a simple movement of his hand, he expanded the shield, destroying it but also causing significant harm to the centipede woman, who hadn't anticipated the shield's sudden disappearance.

The energy released from the barrier began to corrode the monster, which couldn't withstand it. Unlike Iruma's body, this energy became lethal to the repugnant creature.

"Argh!" was the cry of pain from the monster, suffering from exposure to the dangerous divine energy.

"This is divine energy. How the hell do you possess divine energy?" the monster groaned in pain, unable to comprehend how a human could possess such energy.

"I can't die like this!" the monster exclaimed, struggling to withstand the exposure to the dangerous divine energy, which was so similar to that of its master.

"Opera!" shouted a voice that seemed to come from nowhere, snapping Iruma out of his thoughts. Emerging from the shadows was a figure with feline features, red hair, and ambiguous gender.

"Here I am, Lord Sullivan. It seems you've discovered the source of the divine energy from the underworld," said Opera, addressing the mysterious man named Sullivan.

"That's correct, Opera, but what's even more surprising is that it comes from this young human boy. And if you look closely, you might find a striking resemblance," Sullivan said, pointing to Iruma's face, still protected by the energy field.

"That face..." Opera began, immediately recognizing what Sullivan was hinting at.

"It seems, young man, that you will have to come with us," Sullivan declared.

"And if I don't want to?" stammered Iruma, paralyzed by fear.

"Then I will have to devour you right here," Sullivan replied with a smile that sent shivers down Iruma's spine, causing him to nod in fear.

As this conversation took place, a carriage emerged from the ground, pulled by hellish horses that would haunt anyone's nightmares. The carriage was surrounded by luxury, most notably being made entirely of gold.

Iruma was invited to sit inside, and Sullivan joined him, maintaining his cheerful demeanor. The horses neighed and sank back into the earth, leaving Iruma alone in the carriage with Sullivan.

After some time, the carriage slowed down, and Sullivan invited Iruma to look out the window. Still frightened, Iruma peered out and was astonished to see a city as white as ivory, with black accents resembling pearls.

It was a dream-like city for any human, except for the inhabitants who roamed its streets. They all had humanoid forms but lacked skin - they were mere skeletons dressed in human clothing, yet the city was fully alive.

"These are Grim Reapers, spirits from Hades' realm of death, and servants of the man we are about to meet, Iruma-kun," Sullivan explained, adopting a more friendly tone with the awed and frightened child.

The journey continued, and they left the city behind, heading toward a colossal castle with thirteen symbols on its gates. Three of those symbols stood out - a lightning bolt, a trident, and, above them all, a helmet.

The entrance to the castle was a display of opulence and economic power. Precious materials adorned the floor, and the carriage moved smoothly over them until it reached a luxurious carpet.

The carriage eventually stopped, and Opera stepped out to open the doors. As they did, the mansion's servant spirits, all beautiful women dressed as European maids, welcomed them.

"I hope you had a pleasant journey. The master awaits you in the throne room," said one of the maids, who appeared to be the eldest but retained her beauty.

"Thank you for the warm welcome, and you nymphs are always so beautiful," Sullivan replied. "Iruma-kun, why don't you step out?"

Sullivan extended his hand, inviting the still-confused Iruma to disembark. Iruma accepted, still feeling overwhelmed. As he stepped out, he saw a vast open space covered by a purple sky, with decorations and colors that made it a feast for the eyes.

However, he couldn't ignore the curious and astonished looks from the maids, who couldn't help but feel a strange familiarity emanating from the boy – an affinity to nature that made them question why a human child carried such energy.

Iruma followed Sullivan as they walked through the main hall, where a large number of employees cleared the path for them. Iruma noticed various skeletal beings similar to those he had seen in the city, as well as many other humanoid creatures.

The memory of the female monster still haunted him, so he walked behind Sullivan, trembling in fear.

"Don't worry, nothing will eat you unless they want to die," Sullivan said with amusement as they continued through the castle.

After a short while, they arrived at a grand hallway leading to an enormous black door that seemed to be made of platinum.

Along the hallway, there were several paintings of women, but Iruma didn't pay much attention to them until he reached the last one. He found himself looking at a beautiful woman with blue hair dressed in a traditional Japanese kimono.

Seeing this image, Iruma mustered the courage to ask a question, but he was interrupted as the enormous door swung open. A black carpet leading to a throne caught Iruma's attention.

Iruma couldn't describe the room or its inhabitants because his mind was paralyzed when he saw the creature seated on the throne.

It was an immense skeleton dressed in ceremonial attire. Its eyes fixed on Iruma, and its presence seemed to fill the room. Overwhelmed, Iruma hid behind Sullivan.

"Ah, what brings you here, Sullivan, and I hope it's not another ridiculous attempt to teach our high-ranking officers something useless," said the voice from the throne, sounding tired and as if it expected a brief visit.

"Oh, my Lord Hades, always so eloquent. And may I remind you that those lessons were necessary to avoid losing again in the Olympiads against Lord Poseidon's servants," Sullivan replied cheerfully, ignoring Hades's indifferent attitude.

Hades, the name sounded familiar to Iruma, and as he wracked his memory, he remembered a book about world gods in which he had come across this name.

(Hades, the god of the underworld in Greek mythology... Are the gods real, and what does a god want with me?)

These thoughts raced through Iruma's mind as he remained hidden behind Sullivan, hoping to go unnoticed. But that was never going to be Sullivan's intention.

"But I haven't come for that, my Lord," Sullivan continued, turning Iruma to face Hades directly.

From his vantage point, Iruma could see many smaller skeletal figures in the room, all radiating immense power, but with a much warmer demeanor.

"A human child? Why have you brought a human child into my presence?" Hades inquired, masking his displeasure at the intrusion into his sanctum.

"Wise as a king, yet blind as a man... Why don't you take a closer look at the boy's face or feel his energy?" Sullivan asked playfully, making Iruma feel like a sacrificial offering.

Hades, wanting to get this over with quickly, examined the boy's energy. As he did so, his boredom transformed into rapt attention. He rose from his throne and walked toward Iruma.

Iruma, now with the giant skeleton so close, realized just how enormous it was. However, he also felt that the indifferent attitude was giving way to something warmer.

"Child, how can you possess this energy... Let me see your face," Hades said, taking Iruma's face in his skeletal hands and examining him closely. He seemed astonished by what he saw.

Iruma felt uncomfortable with the god's proximity and found the courage to speak. "I am alive, or at least I think I am. But why do you speak of my mother as if you know her?"

Hades's words and actions puzzled Iruma, who was growing increasingly curious about the god's knowledge of his mother.

The response from Hades was unexpected. Instead of the previously indifferent attitude, his tone softened, and his eyes, or rather, empty eye sockets, seemed to display a warm smile.

"Tell me, young one, what kind of father wouldn't recognize his own child?" Hades said with joy, his excitement making the room's inhabitants gasp in astonishment.

As Iruma continued to hide behind Sullivan, he couldn't help but wonder about the god's words. His mind was spinning with questions about the gods, his mother, and his own existence.

Before he could make sense of it all, Hades stood up, his enthusiasm still apparent. "My child is alive and has returned home! He's alive and has come back home!" he exclaimed with genuine joy.

Iruma's presence seemed to overwhelm him, and the god's excitement was palpable. However, the shock and emotional weight of the situation became too much for Iruma to bear. He collapsed onto Hades's throne, unconscious.

In the end, the first action of the Prince of the Underworld was to faint on his father's throne before his most trusted men, leaving everyone in the room astonished.

This is a story created after realizing that the underworlds of "High School DxD" and "Mairimashita! Iruma-kun" had many common elements that could lead to an interesting connection. However, as it is a crossover, I took the liberty to make a change, and that change is the character of Hades. In "High School DxD," Hades is portrayed as a typical Disney-esque villain, but in this story, I decided to depict him as one of the more decent gods from that pantheon. To get closer to his mythological version, I will use the Hades from "Record of Ragnarok" as the paternal figure for Iruma, who bears a resemblance to Iruma's dark form.