Disclaimer: I do not own the rights to Naruto, High School DxD, or any of the other manga/anime that may be referenced over the course of this story.

The Second Son - Prologue

The underworld is a lot like the human world in many ways, but there are subtle differences that easily distinguish the two. The y are both roughly the same size, but the underworld has a much larger land mass due to there not being any oceans. Instead of a blue sky with a day and night cycle, the sky in the underworld is purple and void of a sun or a moon.

Devils, being creatures driven by desire, tend to live more extravagantly than humans. Instead of simple houses and apartments, most devil families live in large mansions or castles. One such devil family lives in a large stone brick castle near one of the underworlds largest cities, Lilith.

This castle belongs to one of the most powerful families among the 72 pillars. The pillars consist of the most politically recognized or powerful families in the underworld. Some of the pillars are renowned to be more powerful than the others; one of these well-known clans is the Gremory Family.

The house of Gremory is well known throughout the underworld as one of the strongest pillars in devil society. The devils of this family are famous because of their superior magic talent and huge magical reserves. The newest addition to the house is also becoming known for more than just his magical talent and reserves though.

When Venelana Bael married into the house of Gremory, the next child born to the house also received the Bael family's signature power. The power of destruction, which is a type of demonic energy that grants the user explosive attack power that can annihilate anything in its path. When Lord Gremory and Vanelana had their first child, he was gifted with the power of both clans, resulting in a child with extreme potential.

That being the case, it was clear to all of those within devil society, that the house of Gremory is well deserving of their position in society.

Anyway, back to their castle. Currently sitting on one of the balconies connected to the prestigious castle were three young teenagers. The first of the group was none other than the Gremory's famous son, the Gremory Prince, said to have the potential to become one of the most powerful devils that the underworld will ever know.

The sixteen year old devil is wearing a plain white shirt with red trimming on the sleeves. He is wearing simple black jeans and shoes, but the most prominent part of his appearance is his hair. His hair is another trait that he inherited from his genetics, the famous crimson red hair of the Gremory house. His hair is medium length and rather messy.

His name is Sirzechs Gremory, and he is currently leaning against the edge of the balcony, looking at his best friend with worry in his eyes.

The second member of the group on the balcony is sitting on a chair and looking in the same direction as Sirzechs, with just as much worry in her eyes, if not more. The girl has long black hair tied into twin tails that reach down to her shoulders. She is wearing a simple pink and blue top with white sleeves and blue jeans. Although she looks slightly younger than her two friends she is also sixteen years old. This girls name is Serafall Sitri.

The Sitri clan is another one of the highest ranking families among the 72 pillars. The house of Sitri is recognized for their advanced knowledge in healing magic, and they also specialize in water based magic.

Serafall is just as famous amongst devil society as Sirzechs due to her ice-based magic. Unlike the rest of the family who specializes in water based magic, Serafall is known for her talent with ice. She is also considered to be one of the most powerful young devils with potential for great things.

Serafall is currently sitting on a balcony at Gremory Caste with her two best friends. Just like Sirzechs, she has her vision focused on the third member of the group. Her eyes display so much sadness and concern for her best friend and crush, although she hasn't admitted the crush part to anyone.

Finally the third member of the young group. Just like them he is also sixteen years old and from one of the most prominent devil families in the underworld. The third teenager has short spiky blonde hair and azure blue eyes. He is wearing a plain orange tee-shirt and black jeans. He also has a black choker around his neck with the kanji for gajin or outsider on it.

His name is Naruto Uzumaki-Phenex.

Unlike Sirzechs and Serafall, Naruto isn't a pure blood devil. His father is Lord Phenex, the head of the Phenex clan. But his mother was Kushina Uzumaki, a human woman that he met during his travels to the human world.

When he met Kushina, they fell in love at first sight. He wanted to bring her back with him to the underworld, but knew that already having a wife and son would make this impossible. Instead he decided to keep the nature of their relationship secret from his family. Although he thought it was true love, after merely a year he got bored of the human woman, but not before she gave birth to his second son.

Kushina Uzumaki died giving birth to Naruto, with her dying wish be that his father takes care of him. Because of this Naruto was taken by his father back to the underworld to grow up as part of the Phenex clan.

When Lord Phenex returned to the underworld with a new born son, his wife was livid. She had no idea about his relationship with Kushina and was furious when she found out that he bought the child back with him. She knew that they couldn't just abandon the baby, so she grudgingly agreed to letting the baby join their family.

Although he is considered to be part of the Phenex clan, he was forced to take the name 'Uzumaki-Phenex.' This served as a way for Naruto to remember his place. Being the bastard born son of the Phenex clan, he grew up despised by most of his so called family. Lady Phenex even went so far as to use magic to force him to wear the choker with the outsider kanji, around his neck at all times.

Being born half human and half devil means that Naruto is nowhere near as powerful as his two friends. He still retains the traits of the Phenex clan, but to a much lower extent. Because of this he is nowhere near as well known or as popular as his two friends.

Naruto is currently leaning against the rail of the balcony a few meters away from the other two, and looking up at the empty purple sky. While his friend's faces show worry, sadness and concern, Naruto's face is void of any emotion.

"Naru-chan… What happened?" Serafall asked her friend hesitantly.

"I was born." He answered instantly with no emotion in his voice.

"W-What does that even mean?" She asked him, standing up and moving to his side, putting her hand over his.

"For as long as I can remember I've been told that I was a mistake." He told her with some anger creeping into his voice. "This damn thing is proof of that!" He growled, pulling on the choker around his neck. "Maybe it would have just been better if I was never born."

"..."

*Slap*

Naruto turned to look at Serafall, not even bothering to acknowledge the stinging feeling in his cheek. He could see tears welling up in the sides of her eyes and a furious expression take over her face. "Don't you dare say that!" She yelled at him

"It's true though-" He started with a cynical tone before…

*Slap*

"..."

Now that both of his cheeks are stinging from the powerful slaps that Serafall sent his way, he sighed and turned away from her, looking back up at the empty sky.

"What happened Naruto-kun?" Sirzechs spoke up, trying to save his best friend from Serafall's rage. "I know life isn't exactly… Pleasant, for you sometimes. But you've never said anything like this before."

Naruto hesitated, considering how to respond. "Just another wonderful birthday I suppose…" Naruto muttered.

"T-Today is your birthday?" Serafall asked dumbfounded. "You've never told us when your birthday is, no matter how many times we asked you!"

"I never really saw the point... Everyone in my family pretends that my birthday doesn't exist. So why should I bother celebrating it?" He asked her rhetorically.

Serafall sighed sadly. This is the worst that she's ever seen Naruto. He's had a few rough patches over the years, but today was different. He sounded so... Sick of everything... He sounded as though he's given up.

"Something must have happened. Something bad. I've never seen you so dejected before Naruto-kun." Sirzechs stated with concern evident in his voice.

Serafall and Sirzechs both turned to their blonde friend waiting for him to answer. There was a few minutes of quiet before Naruto broke the silence.

"Every year on my birthday, Lady Phenex gives all of the maids the day off and takes Ruval out for the entire day. Leaving me at home alone with Otousan…" He started to explain, his voice barely above a whisper. "Usually he just locks himself in the study and pretends that I don't exist."

Serafall and Sirzechs listened patiently, waiting for him to get through whatever it is that was clearly affecting him so much.

"This afternoon though, he came out of his study… I was in my room, when I heard him calling out to me. I was hesitant at first, but he kept on calling to me so I finally went to see what he wanted... When I found him I could smell the alcohol coming off of him…" Naruto paused for a moment, clenching his fist before continuing. "When I found him, he started screaming at me. He told me that I am a disgrace to his family. He told me that I never should have been born. H-He told me that he wished I died along with my mother when I was born…"

When he finished, Serafall gasped in shock at what he was telling them. Naruto has never told them about his mother, apart from the fact that she was human. She had no idea that his mother died during child birth.

Sirzechs' eyes narrowed in fury when he heard this and his fists clenched angrily.

"That's not all…" Naruto said to get their attention again.

Finally he turned to face his two friends. They could see the anguish in his eyes and were slightly confused when he started to take his shirt off. When he finished pulling it over his head he looked up at them to see their reactions.

He noticed Sirzechs almost break the handrail that he was now gripping tightly, as a red aura slowly started to surround his body. Serafall on the other hand looked mortified, and tears actually started to flow down her cheeks.

"…" They were both frozen in shock, completely speechless.

After a few moments, the black haired girl regained a little bit of composure and stepped closer to Naruto. She raised her had to his chest and softly traced a circle around his heart.

"Naru-chan… Let me bring you to my family…They can fix this..." She pleaded.

On the left side of Naruto's chest, over the spot where his heart is, is a fresh burn mark. It was roughly the size of a fist and there was a slight scorch mark around the edges. Directly over his heart was raw, burnt skin that was already beginning to scar.

"No." He replied instantly, stepping away from her. "Otousan did this to me and I will never forgive him. I want the scar to remain so that I never forget what he did to me."

"But-" Both his friend tried to protest but were interrupted by him raising his hand to stop them.

"I will never forget how I got this scar, or who gave it to me... And when I come back I will make him pay for everything that he has ever done and said to me." Naruto told his friends with venom in his voice.

Both Serafall and Sirzechs stepped back in shock at the words. Even though Naruto has always had a rough life, he has never let it get to him like this. He has always just played it off like it was no big deal and tried to stay positive. This Naruto was completely different though. Standing in front of them was a Naruto so full of hatred and resentment.

"W-What do you mean, when you come back?" Serafall asked, her voice flooded with concern.

"I'm leaving the underworld. I don't know where I'll go, but I am leaving." He told them blatantly which made them widen their eyes. "I need to get away from this life. I need to live without being despised and looked down upon… I will never be able to do that in the underworld, so I'm leaving... Tonight."

"N-No! Y-You can't leave!" Serafall shouted with even more tears streaming down her cheeks.

"Naruto-kun, you should come and live here with me. You're a brother to me in every way except blood and I'm sure that my parents would happily adopt you." Sirzechs pleaded.

Naruto looked to his two best and only friends and frowned solemnly. "I'm sorry… This is something that I have to do." The anger in his voice was gone now and it was replaced with pain and anguish.

"I won't let you go!" Serafall cried, wrapping her arms around him. "Please don't leave Naruto…" She begged, nuzzling her face into his neck.

He could feel the wetness from her tears on his neck while she hugged him tightly. He hated the fact that she was crying because of him, but this wasn't something he could back down from. He tenderly wrapped his arms around her and squeezed gently for a few minutes.

"Sera-chan…" He whispered, pulling her away so that he could look at her. "Please don't be sad… I'm not sad, so there is no reason for you to be."

"B-But I don't want you to leave…" She sniffed.

"I have to though. This is something that I need to do." He told her softly. "But I promise you that I will come back one day."

She silently looked into his eyes for a few moments, trying to find any hint of deception, but she couldn't. She knew that he was telling her the truth. And she knew that he believe that this was something that he had to do.

"I will hold you to that promise!" She warned him, trying to sound as threatening as possible.

He chuckled softly and offered her a warm smile. Serafall blushed slightly at him giving her such a genuine smile and couldn't help but smile back. Naruto's smiles were infectious. She stood up on her toes so that she could equal him in height and placed a soft kiss on his cheek.

If Naruto wasn't so good at hiding his emotions after all these years, he probably would have blushed right back at her. The feeling of her soft lips pressing against his still stinging cheek felt amazing. When she leant away from him her cheeks were even redder, but the smile was still evident on her face.

Serafall stepped back so that Sirzechs could say his goodbye.

"Are you sure that you won't stay here with me Naruto-kun?" Sirzechs tried one last time. "You know that you're welcome here. I'm pretty sure that my parents like you more than me anyway." He finished with a humorous laugh.

"I appreciate the offer, but as I said, this is something that I need to do. I think that getting away for a while will give me a chance to figure out who I am as a person." Naruto replied genuinely.

Sirzechs simply nodded in acceptance. There wasn't much else he could do. He didn't want his best friend… His brother… To leave, but it would be for his own benefit. He couldn't help but agree that getting away for a while would be good for Naruto.

Sirzechs hid his sadness well, but he hid his anger even better. Right now he was furious. It was a struggle to keep his aura under control, let alone keep the smile on his face. How could the Phenex family get away with treating one of their own members like this? They were one of the top families among the 72 pillars and were respected by the entirety of devil society.

He was distracted from his thought when he felt Naruto pull him into a hug. Filing away his anger for a later time, he returned the embrace. "Stay safe Naruto-kun… If you ever need anything, don't hesitate to contact me." He finished as they pulled away from each other.

"Until next time… Aniki." Naruto said with a smile to Sirzechs.

Sirzechs couldn't help but smile at the term of endearment and with a nod of his head he leant back against the edge of the balcony.

Naruto turned back to Serafall to say his final farewell, but before he could open his mouth she jumped at him again, wrapping her arms around his neck and nuzzling her face against his chest. He still hasn't put his shirt back on by the way…

"I will miss you so much Naru-chan…" She whispered.

"I will miss you too Sera-chan." He told her tenderly, hugging her tightly against his chest.

After several minutes and multiple pleas for him to change his mind, Serafall finally let go of the blonde devil and stepped back to lean against the balcony next to Sirzechs.

"Well… I suppose this is goodbye for now." Naruto said with a smile but felt a bit sad to be leaving his two best friends behind.

"Be safe! / You better come back!" Sirzechs and Serafall told him in that order.

Naruto offered his friends one last genuine smile before turning away from them. He focused his energy and after a few seconds a large magic circle appeared on the ground beneath him. He didn't turn back to face his friends a final time because he knew that if he did he wouldn't be able to leave.

With a deep breath he closed his eyes. The circle slowly rose around his body. When it was above his head, it closed inwards and disappeared.

With that, Naruto was gone.

Author's Note: I hope that you enjoyed the prologue for my story, The Second Son. This was just a bit of an introduction to set up the story. The next chapter will take place after a significant time jump.

All feedback is greatly appreciated so please leave a review or even PM if you'd prefer.

Thanks for reading!