Melody of Memories (NarutoxHighschool-DXD)

Disclaimer: This story is a work of fiction. All the characters, names and places belong to their respective owners.

=[Black and White]=
7

Naruto lowered his blue eyes and narrowed them at the blond-haired girl standing by his side. His hand gripped her smaller one, holding them in comfort while she watched the group of young devils. He'd pondered deeply on the connection he had with her. In her mind, he was her older brother, but to him, was she his little sister?

His mother seemed to think so, adoring her like her own flesh and blood – even more than when he was just a little kid under her devilish wings. He didn't mind his mother focusing her affection on Shiroka. She needed an outlet for her seemingly infinite motherly love anyway, and not having her smothering him at every turn was a devil-send. But from the recent comment Shiroka made, she implied her very existence hinged on Kuroka's own.

For them to be linked through causality meant they were related.

"Are you…?" Naruto asked, pondering if Shiroka was his daughter from the future. Time manipulation was a rare power, not an impossible one. Esdeath's magic affect the flow of time around her, enabled her to literally freeze the time of anyone she chose. The only reason he managed to beat that power was that his own counteracted her ice magic and overwhelmed it, preventing himself from freezing in time.

If time could be freeze then it could be accelerated or reversed.

Shiroka returned the gaze and smiled broadly. She shook her head and returned her golden eyes back onto Kuroka, who was caressing her younger sister. Rias Gremory along with the rest of her peerage surrounded the said girl, looking over Shrione, while Issei was beginning to come about thanked mostly to Asia's effort.

"Shiro is your little sister, Nii-sama," Shiroka assured, warningly. Her fingers curled around his hand and tightened. "Shiro is also Kuro-nee's sister. Without Kuro-nee and Nii-sama, Shiro does not exist."

"Does that mean Shirone is also your sister?" Naruto asked while taking in the information. He already knew the answer before he even asked.

"No, Nii-sama. Shirone is not related to Shiro," Shiroka answered as he expected. If Shirone, known as Koneko to her friends, was her sister then Shiroka would have told Tobi to not hurt Shirone under any circumstance. Tobi vowed to never make Shiroka sad. The fact that Tobi knocked Shirone out without worrying about Shiroka was enough evidence for Naruto.

"Is that so?" Naruto murmured quietly. He frowned thinly as what kind of relationship Shiroka had with Kuroka.

Could Kuroka and Shirone not blood related?

Their appearances – black and white – did give him doubt, but Youkai was a more diverse race than his own. Siblings didn't necessary be similar. He would have to check if they were – but would the answer confirmed what he believed about Shiro? It might and it might not. And if Shiroka was her sister as she claimed to be, her physique was closer to Shirone than Kuroka.

"Will you not tell me the truth?" Naruto asked as more questions surfaced in his mind. Everything felt so clouded where once was cleared as day. He did not wish to constantly doubt himself.

"I don't like being kept in the dark, Shiroka," Naruto continued. "And I don't like being played. I know you're the one who planned all of this. If you did not, you would not have bothered to come with me. I do not know exactly how you managed to trick her into showing up here, knowing the danger of being in the same spot with all four Maous, but I will assume that you have contact inside the Khaos Brigade, and that person is high enough to earn Kuroka's trust and friendship, but will abandon her at your say so. I sensed there was a demonic aura from those paper fliers you paid attention to. If I have to guess, that is your mole – an ultimate class devil."

"Nii-sama is scary," Shiroka commented, shivering lightly. She tried to remove her hand, but found she could not free herself. His grip strengthened while lighting crackled along his fingers. "Are you mad that Shiroka lured you here so you could meet Kuro-nee?"

"No… I'm not mad, not mad at all," Naruto said in a dark, grim tone. He was angry, but not at the reason she had asked. "If I was truly mad, you wouldn't still be standing here. And if I had to blame anyone, I'll blame myself. To be tricked and played mean I have not able to see the full picture and acted foolishly."

"Nii-sama is scary," Shiroka repeated. "Nii-sama wouldn't hurt Shiro… would you, Nii-sama?"

"Only if you were my enemy," Naruto said coldly. He narrowed his blue eyes at her. "Are you my enemy, Shiroka? Tell me the truth."

"I am not your enemy," Shiroka said with a wide cheerful smile. "Is that enough?"

"Yes," Naruto said and loosened his grip. He had not seen the full extent of her powers, but for Nagato to listen to her without questions meant she was as least as powerful as Nagato, and Nagato could be said as the most powerful devil he had ever come across. His mastery over attraction and repulsion of all things made him seemingly untouchable. "As long as you are not my enemy, I will not hurt you, my cute Imouto."

Shiroka giggled while Naruto leveled his eyes and leered at Ajuka Beezelbub, one of the four Satan. The man noticed his gaze despite his eyes was paying attention elsewhere. He gave a light nod. He then did a gesture in the air, indicating something.

Naruto frowned as he got the message. He turned his attention towards Kuroka before disappearing in a crimson flash of lightning. He materialized next to her along with Shiroka and Esdeath. Esdeath seemed to be disorientated.

"At least tell me when you do that, Naruto!" Esdeath growled as she fixed her hat. She jabbed towards her brother – her elder brother – and shouted: "Stop sleeping all the time!"

"Hmmm?" Falbium muttered as he heard his sister in his dream. He gestured a hand at Serafall, calling her to him. The girl tilted her head questioning, but leaned towards Falbium regardless. He whispered something into her ears.

"No! I'm not telling her that! And why did you tell me it!?" Serafall shouted. Her face went red.

"What did my brother say!?" Esdeath bellowed while Naruto face palmed. He knew what Falbium had whispered to Serafall without hearing it. It was the same thing he was told before Esdeath tried to kill him. He beat her up and made her his bishop.

"I can't say!" Serafall responded, but Esdeath glared at her as if she had killed someone precious. "I can't believe I have three mortal enemies now!"

"Much better," Falbium said and dozed off again. He wouldn't have to deal with his sister for a while. He also made a note to enlist his younger brother into the academy. The idiot had been playing around for far too long.

"Don't do anything stupid, Esdeath. And it's time to leave, Kuro-chan," Naruto said, paying his attention to Kuroka, who tried to wake up her unconscious sister. Tobi must have hit her pretty hard. "You will be kept at Akatsuki until your execution. Until then, you will be directly my responsibility."

Kuroka stared up at him – her master. Despite being apart, she still considered him as her one and only master. He had matured greatly in the years that gone by. "Can I have a little more time with Shirone, master? I promise I won't use it to come up with an escape plan nya."

"Let her go, Kuro-chan," Naruto refused and tilted his head towards Rias Gremory. "Your sister is in good hands. Gremory clan treats their servants like family no matter who they are. Even former enemies who out to kill them could become their mistresses and be pardoned of all crimes."

"Hey! Naruto-kun! I tried to kill her too!" Sirzechs Lucifer called out from across the field the instance his wife was mentioned. "And what crimes are you talking about!?"

"Sirzechs-chan shouldn't ear drop on Naru-tan," Serafall defended while paying much attention to the conversation while ignoring Esdeath's death threats. She was the last Maou to befriend Naruto, and the only one among the four to initiate the relationship since she couldn't wait for him to come to her – if he ever bothered to. Her job of dealing with foreign affair – although very important – did not provide any benefit to Akatsuki. They dealt only with devils and devils-related crime. Any other races were not their problem unless it threatened the unity of the Underworld like the Khaos Brigade.

Naruto ignored Sirzechs' outburst and placed his hand on Kuroka's shoulder. He gripped it lightly. "Don't worry, you will see your sister again, Kuro-chan."

"When will that be, master?" Kuroka asked softly and placed her hand over the back of his.

"Soon," Naruto said simply. He crouched down to her level, matching her eyes. "Do you trust me?"

"Even if the world lied to Kuro-chan, Master never will – master promised," Kuroka answered with a big smile, showing her feline teeth. She then brushed her fingers and stroked her little sister's sleeping face one more time before handing Shirone to Rias Gremory. "If anything happens to my sister, I will never forgive you."

"Nothing will happen to her," Rias promised confidently. She looked at her peerages. They agreed with her promise. Their bond was as strong as family.

Naruto did not make any comment despite wanting to.

"I will never let anything happen to Koneko-chan," Issei called out. With what little strength he had left in his fatigued body, he pulled himself off the ground. Asia helped him while muttering his name. She could only heal his injuries, not his exhaustion. Whatever transformation he went through took a lot out of him.

Naruto sighed as he felt a sense of déjà vu while Shiroka stared blankly. It was just a few hours ago that Issei spewed the same thing, and despite getting beaten, the idiot didn't grow up at all. "What did I tell you about making empty promises, Sekiryuutei?"

"You didn't actually say anything, master," Esdeath remarked. She waved her hands dismissively when Naruto rolled his eyes at her. "You need to be stronger to back up your claim, Issei-kun. If you want to become the best, Onee-chan will teach you and maybe you can teach Onee-chan other – Ara? I think I made an enemy – three?"

Rias, Akeno and Asia glared at Esdeath. Their killing intents filled the surrounding.

"I'm scare," Gasper mumbled while hiding behind the silent Yuuto. Xenovia didn't join in the fun.

"It's not an empty promise," Issei called out and manifested his sacred gear, covering his hand. It wasn't the gauntlet of red dragon emperor he was familiar with. It was something else entirely. The blue gems surrounding red and black gauntlet radiated an aura that sapped the strength out of everyone, all while boosting his own.

"Divine Dividing…?" Kuroka gasped in shock. That power belonged to her current leader – not master – and bearer of the White Dragon Emperor, Vali. "Be careful, master."

Naruto stared at the new gauntlet of Boosted Gear for a short moment before outstretching his hand and pinching his little sister's cheek hard. Her golden eyes instantly became watery while she threw her hands about, trying to break free. Her hands gripped his wrist while her legs pushed against him. Still, he did not let her go.

When quite a few people in the area growled at him for hurting Shiroka, including Kuroka, he decided it was enough punishment. "She's faking it."

"Nii-sama is being a meanie! It hurts, Nee-sama," Shiroka called out and raised her short hands towards Kuroka for a hug. She was quickly embraced by the Nekoshou before Serafall could jump in.

"So close," Serafall muttered dejectedly. She then flinched frightfully as she was very close to Esdeath, who now gripping an ice scythe. She immediately backed away before Esdeath chased after her while everyone watched with a sweat-dropped.

"What did you tell Serafall?" Sirzechs asked.

"Do you want another Ice Queen?" Falbium asked.

Sirzechs blinked as his mind clicked. "Ohhhh! Is that why she following Naruto around?"

"Nyaaaaa," Kuroka purred while the bell around her neck jingled by Shiroka.

Naruto rubbed his head each time the bell rang, but did not say anything.

"Wow I'm so powerful now. Maybe I'm an Ultimate Class?" Issei called out as he tried out his upgraded gauntlet. The aura created by the blue crystals intensified, further halving everyone's power and added them to his own. His strength soared to new height.

"Powerful? Ultimate class? Don't fool yourself. You are still weak, Sekiryuutei," Naruto said as lightning crackled around him, amplifying his strength several hundreds fold. "You will always be weak as long as you borrow powers from your Sacred Gear. As long as you rely on it, it is not you that others feared. It is your Sacred Gear, and without it, how strong will you be?"

Issei looked confused. The Sacred Gear was his power, wasn't it?

Naruto sighed and opened his palm. Lightning crackled between his fingers. The four Satan immediately became attentive including the previously sleeping Falbium. Sirzechs was about to leave his seat in order to stop the imminent attack against his future brother-in-law. Ajuka stopped him, however.

"It will be a good lesson," Ajuka said thoughtfully.

"I will teach you what it meant to fight on your own strength and earn powers that you could call your own," Naruto said as he compacted and condensed his lighting into a small rod. He fired the lighting rod at Issei. The speed it flew was far beyond Issei's ability to evade so he attempted to block it instead.

"So when did you learn that he completed it?" Ajuka asked, curiously, while Sirzechs relaxed a little.

"Naruto-kun had used it against my peerages," Sirzechs responded, frowningly. "Even now, they are still crippled, unable to access their full powers. I know he always is looking for an advantage over those that he designed as enemies, but things aren't always what he sees. I honestly do not approve of this method being used on our would-be allies. What is the point of crippling a person who was starting to learn and understand what he has?"

Ajuka paused for a moment. "Do you not believe in Sekiryuutei-kun?"

Sirzechs eyed him and then chuckled. "I guess I'm not a very good brother-in-law huh? Very well, I will believe in Issei-kun; may he overcome this obstacle."

Issei screamed aguishly as lighting wrapped around him. The lighting rod descended into his body, while passing through his flesh unhindered. The dragon within him squirmed and roared as the link it had with its host was forcibly disrupted.

"Issei!" Ddraig called out as loud as it could, but its host could no longer hear it. "Hang in there!"

"Issei/-kun!" All of his friends called and rushed to him. The moment they reached him, he collapsed onto the ground on all four, panting profusely. Beads of sweat ran down the side of his face while the gauntlet around his hand vanished.

"Ddraig?" Issei called out while looking at his hand. No dragon responded.

"What did you do to Issei!?" Rias demanded, but Naruto did not pay any attention to her. "Naruto! Tell me!"

"Shut up, Gremory. If you've taught your pawn better then he would stop flaunting around powers that isn't his – isn't even belonging to our kind. And you, Issei, show me that you can stand in front of me on your own power. Until then, you don't deserve to be called a devil," Naruto said before he vanished in a crimson flash along with his peerages as well as the speechless Kuroka.

"Rias," Sirzechs said as he landed next to the group after he told everyone to disperse. "Everything will be fine."

"Nii-sama," Rias greeted. "What did Naruto do to Issei?"

"Naruto-kun has disabled his Sacred Gear," Sirzechs answered while giving a quick glance at Issei, who was laughing weakly at his predicament. Even powerless, there was fire burning in his eyes, which had earned Sirzechs' approval. "Until Issei-kun can overcome the restriction placed upon him by Naruto-kun, he will not be able to access his Sacred Gear."

"Uzumaki-san can do something like that?" Yuuto asked, shocked.

"Naruto-kun didn't disable it. The more correct term would be severed the connection between Issei and Ddraig, thus preventing Issei from activating any of Ddraig's power," Ajuka said as he approached the group. He examined Issei for a little while before smiling. "While we constantly researched on how to duplicate God's work as well as improving a wielder's potential, Naruto went the opposite direction by using mine and Azazel's research. He didn't want to improve the synchronization of a host and his or her Sacred Gear. Instead, he wished to disrupt or distort the bond. In doing so, he created a technique that inhibits a wielder's ability to channel the power of a Sacred Gear."

"Ajuka-sama," Rias called politely. "Can you help Issei?"

"I can," Ajuka answered and looked over the group. "But I afraid I won't. This is for your own good too, Rias-chan. You must learn to master your abilities and prowess as a part of our race without relying on your Sacred Gear completely. More than half your peerage is relying on it right now, and one day it will be turned against you. How will you defend all those that you cared about then?"

"Don't be so down, everyone," Serafall called out when the young devils saddened. "Just stand on your own power and then Naru-tan will acknowledge you. Right now, he's moody because … well Naru-tan is always moody. I know! I will go and cheer him up."

"Is no one going to stop her?" Yuuto asked while Serafall ran off to break into Akatsuki – again.

"A few days in jail will do her good, and I wish she would come out and admit it," Ajuka said. "When she gets rejected, she will refocus on her work rather than heading there every couple of days on some false pretense."

– To be continued –

I wonder if I should tell you exactly what Shiroka is, but it's fun to have you guys guessing. Remember that when Shiroka says "I" then she is telling the truth. And this story is about the relationship between Naruto and Kuroka, not about the cannon plots. Story doesn't follow cannon plot anyway.