It was the 25th of March, 2096. It was a quarter to midnight, Miyuki's 16th birthday was just about to end. Tatsuya and Miyuki had spent the whole day celebrating and they were now at home. They had spent the day in joyful celebration, both seemingly ignorant of the significance this day presented to a girl of Miyuki's stature. Perhaps ignorance is an inaccurate word to use, both siblings were well aware of the significance of this day, but both deliberately chose to ignore it; there was a willful denial and reluctance to acknowledge that the grim future they had both feared was now more imminent than ever.

Miyuki was now of marriageable age and soon she will be separated from her beloved brother. Both Tatsuya and Miyuki were well aware of this inevitability, they had been agonizing over this prospect the day before, but neither broached the subject during their day together.

For Miyuki, the prospect of marrying any man other Tatsuya was detestable, no the prospect of any other man touching her other that Tatsuya was outright abhorrent. To Miyuki, her entire being belonged to Tatsuya. She existed solely for him. These were her true feelings. Her body yearned for his touch and her very soul only wished to be with him, to be of use to him, to support him, to care for him, to love him. To be one with him in mind, body and soul that was Miyuki's true desire. Miyuki loved Tatsuya more than anything else and it pained her to remember that she could not be with him in the way that she desired. During the times that she thought about it too deeply, Miyuki felt physical pain. It felt as though sharp needles were thrust into her chest and she could barely breathe. A future away from Tatsuya was something she could not bear to think of and yet the day has come where it was no longer just a faraway possibility but a rapidly forthcoming inevitability. The saving grace to all of this was that while that future was near it would not come to pass as soon as she had expected. Miyuki still had time to be with Tatsuya.

Yesterday, Miyuki was plagued by anxiety and this anxiety was far from misplaced. Society had placed extraordinary pressure on female magicians to marry early and give birth to many children. It was not unheard of to hear that a girl's engagement was registered on the day of her sixteenth birthday. And Miyuki feared that would be her reality, that on the eve of her 16th birthday she would receive a call or message informing her that her betrothed had already been decided.

Magic is power and magicians are an important military power for the nation. The state needed a wealth of excellent magicians and this was something the magician community understood and dutifully provided. The truth of the matter is that for all the power magicians wielded, they were still a very small minority compared to ordinary humans and thus needed state protection. The magician community needed the government just as the government needed magicians. The current status quo fueled by this symbiotic relationship was the foundation of society's expectation for Miyuki to marry and have children.

Miyuki sat the pinnacle of Japanese Magic Society. She is a direct descendant of Japan's strongest magician family, the Yotsuba Family, and a candidate for the next family head. It was not only her duty as a daughter of the Yotsuba but it was also her duty to the nation to pass on her own exceptional magical ability to her offspring. Miyuki took solace in the fact that due to her high status and exceptional ability, finding a suitable partner for her would not be easy. Even in families of other excellent magicians, there were few children her age whose fiancé has been decided. The partner chosen for her needed to be suitable for the future head of the Yotsuba and that would not be an easy find.

The Yotsuba lived in a specific way and outsiders would find it hard to adapt. Miyuki knew the decision of who her future husband was going to be will not be made lightly and thus she still had time to live peacefully with Tatsuya. But anxiety still clouded her heart. Either way, the fate that she will get married in the not too distant future will not change. The possibility that her aunt Yotsuba Maya will suddenly produce a fiancé for her and that she will be married within the month is not small. Miyuki resigned herself to her fate as she stared at a picture of Tatsuya, lightly caressing his image with the tips of her fingers, her eyes filled with melancholic longing.

Tatsuya was outside Miyuki's door. He had wanted to greet her one more time before her birthday was officially over but he stood paralyzed. He had been standing in front of her door for a while but could not bring himself to knock on her door. He stood there contemplating what had lead up to his indecision.

Just as Miyuki was afflicted by deep dread and anxiety over her 16th birthday, Tatsuya was also in deep thought yesterday. Tatsuya for one welcomed Miyuki's birthday. This day was sacred to him and it would be the fourth time he would be able to celebrate it openly with Miyuki. In his youth, Tatsuya was not allowed such a simple luxury such as to celebrate Miyuki's birthday with her. He had always been treated as a servant and up until a few years ago, he had only conversed with Miyuki as her guardian. Though Tatsuya and Miyuki enjoyed a very close relationship now, which at times crossed the boundary of sibling love and they acted more like intimate lovers than siblings much to their friends' confusion and the pair's amusement, nothing has changed within the Yotsuba's hierarchy. Tatsuya was still a servant and still Miyuki's guardian.

Tatsuya found the assignment to be Miyuki's guardian a blessing. As her guardian, it was unnecessary for him to leave Miyuki's side for extended periods of time. In fact, a command to make Miyuki's safety his number one priority was one he openly welcomed. There was no one he cherished more than Miyuki and Tatsuya would gladly lay his life for her if needed. A world in which Miyuki did not exist was something Tatsuya could not comprehend. Miyuki was the only person he could and does genuinely love. If Miyuki were to disappear from Tatsuya, he would no longer have a reason to live. These were Tatsuya's true feelings. A world that robbed Miyuki away from him was a world that he would not permit to exist. Tatsuya had the power to make this apocalyptic catastrophe come into fruition but so long as Miyuki lived, he had no reason to commit such a deed.

Tatsuya also felt a certain loneliness. He understood that with Miyuki turning sixteen, his days as Miyuki's guardian were numbered. He knew that when Miyuki is married no husband would allow him to be in such close proximity with her as a member of the opposite sex. Tatsuya was loathed to relinquish his guardianship but he knew he could still protect Miyuki; despite everything he was still going to protect her even if he was no longer her guardian.

Miyuki's future husband, this mystery man plagued Tatsuya's thoughts relentlessly. Tatsuya had wondered what type of man would be lucky enough to marry Miyuki. In Tatsuya's eyes, Miyuki was special. Miyuki's future groom needed to be someone who was suitable for Miyuki. He didn't need to be more powerful or smarter, nothing as superficial as that. What Tatsuya was concerned about was Miyuki's happiness. Tatsuya had seen how his parents were trapped in a loveless marriage. Their mother suffered greatly while their father was absent most of their lives. They were both deeply unhappy and that was a fate Tatsuya would not allow to befall on Miyuki. More than anything, Tatsuya wanted Miyuki to be happy but regrettably, he knew he could not make her happy. He could not marry Miyuki, Tatsuya knew this. The next best thing for Tatsuya was to vet Miyuki's would be spouse. This man must be able to defeat him combat and more so than anything, he had to be suitable for Miyuki, these were Tatsuya's conditions. He would not compromise on these two points even if the groom were handpicked by their aunt Yotsuba Maya herself. Tatsuya was going to exercise his right as Miyuki's older brother to demand a duel. This man needed to not only defeat Tatsuya in combat but also love Miyuki. This man needed to be able to hold Miyuki in his heart and cherish her. He needed to be able to build a family with her. He needed to be able to make Miyuki happy.

Tatsuya was pulled out of his thoughts when he heard sobbing from the other side of the door. Tatsuya, now frantic, opened the door to find Miyuki crying at her desk while holding a picture of himself.

Miyuki was unaware that Tatsuya was standing outside her door. She thought he was still downstairs in the laboratory and she didn't expect him to hear her crying much less burst through her door. Miyuki was at her desk holding a picture of Tatsuya. She was lightly grazing her fingertips against the glass when she found tears start to drop on the frame. Miyuki was again lost in thought and the familiar feeling of needles in her chest had returned. Her mind had wandered once again to that unpleasant place, to the future where she could not be with Tatsuya. Miyuki let out painful sobs.

Tatsuya ran to Miyuki and kneeled before her to catch her downcast eyes. When their eyes met, he gently wiped away her tears.

Miyuki met Tatsuya's gaze and it was full of concern and warmth. His eyes seemed to tell her that everything will be okay, that he was here for her. Tatsuya took Miyuki's hands in his and held them firmly. His hands were warm and Miyuki relaxed at his touch. Seeing Miyuki relax slightly, Tatsuya thought it be best to ask her now about what troubled her. Though Tatsuya was definitely no master at emotions, seeing Miyuki this unhappy pained him and he would do anything to make her smile again. But before he could help Miyuki, he needed to know the problem and judging from the frame she was holding, he was part of the problem.

"Miyuki, what is the matter?" Tatsuya said gently while lovingly gazing into Miyuki's eyes.

Tatsuya's concern deeply moved Miyuki and she was melting under his gaze but Miyuki did not want to saddle Tatsuya with her problems. No, confessing her feelings would only worsen the situation. Miyuki knew that Tatsuya only saw her as his little sister and confessing her feelings to him would only make him want to leave her. She steeled herself and closed off her heart.

"Nothing is the matter, Onii-sama. I'm sorry to have made you worry." Miyuki put on an unconvincing smile.

Tatsuya frowned. Something was clearly wrong but Miyuki would not tell him. Tatsuya directed his gaze towards the picture on Miyuki's desk.

"Miyuki, something is clearly wrong. You wouldn't be crying like this if everything is okay." Tatsuya's tone while gentle implored Miyuki to open up to him, to lean on him. Tatsuya then turned his attention to his photograph "Miyuki, if I did something wrong please..." Miyuki cut him off.

"No! Onii-sama did nothing of the sort! Onii-sama has always been so kind to Miyuki, he did nothing wrong!" Miyuki rebutted.

"Okay, but please won't you tell me why you're so sad? It pains me to see you so unhappy. I would like for you to tell me so I can help you." Tatsuya's gaze did not waver. His eyes full of concern and his grip on Miyuki's hands held firm. He wanted to show he could be her rock. Someone she could depend on.

Miyuki's voice cracked as she tried to stifle another sob. She was causing trouble for Tatsuya again. Her heart could not bear this. She felt extremely guilty at burdening Tatsuya. She felt deeply unsettled by the prospect of marriage. She felt the loneliness of unrequited love. She felt anxiety at the thought that at any moment they could be separated. Moreover Tatsuya was still looking at her with loving eyes. She was melting and all her defenses were weakening under this gaze, coupled with the dizzying array of emotions clouding her mind; Miyuki snapped.

Miyuki collapsed into Tatsuya's chest and wailed.

"Onii-sama, the reason why Miyuki is so unhappy is because she doesn't want to get married!" Tatsuya's eyes widened and it felt like a heavy rock fell into his stomach. He didn't know that Miyuki's betrothed had already been announced. He wrapped his arms around Miyuki and held her tight. He then put one hand on her head and started stroking her hair.

"Don't worry Miyuki, whoever that man is, I will personally vet him to make sure he is a suitable partner for you." Tatsuya said reassuringly.

Miyuki realized that Tatsuya had misunderstood her statement. Miyuki had two options, she could go along with the misunderstanding and simply "correct him" saying that while no fiancé had been announced, she was terrified of marrying a stranger, or Miyuki could tell the truth. Miyuki's mind told her to lie but seeing Tatsuya so concerned about her, her heart would not allow her to keep lying. Miyuki had already reached past her breaking point and the flood of emotions she was feeling now clouded her judgement. Miyuki's heart won over her head.

Miyuki sat up and looked at Tatsuya in the eyes. Her body was trembling and she clenched her hands firmly on her thighs. She exhaled deeply to steady her breathing. It was now or never.

"No, Onii-sama. There is no announcement yet regarding the identity of my fiancé."

"Then why were you crying?" Tatsuya's asked puzzled. Miyuki grabbed Tatsuya's hands and hugged it to her chest.

"It's because...It's because I do not wish to marry anyone...I do not wish to marry anyone else but Onii-sama! I want to be Onii-sama's bride! I want Onii-sama to treasure me as a woman!" Miyuki cried, desperation clear in her voice.

Tatsuya was wide eyed with shock. He felt like he had misheard Miyuki but that was not possible. He had honed his five senses to their absolute peak, which only meant that...

"Yes! I love you. I'm in love with Onii-sama!" Tears once again streamed down Miyuki's face.

Tatsuya sat frozen, blinking in confusion. He did not know that this was how Miyuki felt. Granted, Miyuki had always been affectionate towards him but he just assumed that was just her showing her affection towards him as her brother. He never imagined Miyuki to feel this way, to feel the same way he did.

"But, Onii-sama is normal after all…You have a normal sense of morality too…You wouldn't carry a romantic feelings for your own sister right."

Tatsuya couldn't get a word in, his mind was still processing Miyuki's earlier statement. Emotions were not his strong suit and this conversation was one he definitely never saw himself having.

"It's fine even if you want to hate me for being such an abnormal sister! It's fine even if you consider that these bad feelings are an unnatural tendency! But…, please. I beg you Onii-sama…"

Miyuki raised her face, wet with tears.

Tatsuya had never seen such a sorrowful desperate face be so beautiful. Tatsuya felt immense guilt when he looked into Miyuki's eyes and only saw desperation.

"Somehow…Somehow…Please let me be by your side. Please don't be detached from me. Please don't disappear from my side!" Miyuki continued to sob while clinging on to Tatsuya's hands in her chest.

Even when she was crying, Miyuki didn't distort her face. It was her beautiful face, just showered in tears. Tatsuya was enamored by Miyuki's face but he also felt immense guilt. Tatsuya gently freed his hands from Miyuki's grasp and quickly pulled Miyuki into a tight embrace.

Panic flew across Miyuki's face for a split second but she quickly relaxed when she felt Tatsuya's arms wrapping around her. Her shoulders relaxed and she entrusted her body completely to Tatsuya. She buried her face in Tatsuya's chest.

"Miyuki..." Tatsuya whispered gently into Miyuki's ear.

"Onii-sama..." Miyuki immediately looked up at Tatsuya and was greeted with his warm loving smile.

"I love you too, Miyuki. I love you as a woman." Tatsuya said with so much warmth, it was hard to imagine that this man had limited emotional range.

"Again...could you say that again please, Onii-sama?" Miyuki asked fearfully. It was now time for her to doubt her own senses.

Tatsuya smiled at his sister warmly.

"I love you, Miyuki. I will never leave you. I will never reject you. I will stand by your side 'til death do us part."

Miyuki laid her head on Tatsuya chest and he stroked her hair.

"I'm sorry Miyuki...that you cried because of me." Tatsuya said meekly. He still felt guilty at being so oblivious to his sister's feelings.

Miyuki quickly looked up at him.

"No! Onii-sama has nothing to apologize for! Miyuki is very happy to know that her Onii-sama feels the same way!" Miyuki protested with flushed cheeks. It was true. Miyuki had been in love with Tatsuya for a while now. It started out when she saw him as a "dreamy member of the opposite sex" during her training at Miyakishima all those years ago.

She had first dismissed those feelings as just her awkwardness at her inability to interact with Tatsuya and she hoped they would fade away on their own once they became more familiar with each other but these feelings never dissipated. Instead, these feelings only grew more intense that she could no longer deny the fact that she was in-love with Tatsuya. Miyuki was extremely elated to hear Tatsuya reciprocate her feelings.

Miyuki's flushed face enamored Tatsuya. To hear Miyuki confess her love for him set his heart a flame. The normally stoic Tatsuya, had no emotional limiters when it came to Miyuki and now it felt like a dam had broken in his mind and many emotions surged through his mind. Tatsuya felt excitement and joy at the fact that Miyuki felt the same as him, fear and anxiety still remained at the prospect of Miyuki getting married and now there was apprehension at the unknown. Tatsuya had never planned on revealing his feelings to Miyuki. Tatsuya knew his place and played his part well. He never planned on burdening Miyuki with his own emotions so the fact that he had just revealed his true feelings to Miyuki made him uneasy. Tatsuya was in unchartered territory and navigating his own emotions was not something he was used to. Tatsuya looked at Miyuki and held her hand.

"Miyuki, perhaps we should get off the floor." Tatsuya smiled wryly. Miyuki flushed and dipped her head in embarrassment. It was very unladylike to be sitting on the floor, in such close proximity with a member of the opposite sex.

"Yes, Onii-sama!" Miyuki's voice was a pitch higher as she quickly rose to her feet. Tatsuya looked on amused at his cute little sister.

When they were both on their feet Tatsuya stood in front of Miyuki.

"Miyuki..." Tatsuya called and Miyuki looked up at Tatsuya eagerly. Tatsuya found her expressions to be very cute. Tatsuya had not fully regained his senses and his emotions still controlled most of his actions. Tatsuya slid his right hand under Miyuki's chin, tilting her face upwards to meet his. He moved his face forward and Miyuki closed her eyes expectantly, the distance between them grew smaller and approached zero. Tatsuya gently kissed Miyuki on the lips. He felt her soft pillowy lips against his and she felt his lips against hers. It was only for a moment but Miyuki was elated. Her face was burning bright red.

Tatsuya had realized what he had just done and blushed lightly.

"I'm sorry Miyuki. I guess I should have asked before I kissed you." Tatsuya said sheepishly.

"No...Onii-sama has nothing to apologize for...Miyuki...Miyuki quite enjoyed it." Miyuki stuttered as she was blushing all the way to the tips of her ears.

"Perhaps, we should go to sleep now." Though Tatsuya tried to regain his composure he was still visibly embarrassed. He was now directing his gaze at the door, avoiding looking at Miyuki, his face lightly flushed. Miyuki found this reaction to be adorable and giggled. She had never seen Tatsuya this embarrassed before.

"Yes, Onii-sama." Miyuki smiled brightly. Her mood difference was evident and she had regained her bearings much faster than Tatsuya.

"Let me walk you out the door, Onii-sama"

Tatsuya nodded. Truthfully Miyuki had wanted Tatsuya to spend the night in her room. Though Miyuki felt as if a huge weight had been lifted off her shoulders after her confession to Tatsuya and his reciprocation of her feelings only made her want to jump with joy, she still couldn't shake her earlier anxiety. The fact of the matter was that she will soon be married to a man that would not be Tatsuya.

In truth, Tatsuya did not want to leave Miyuki's room. He wanted to spent the night with her. Too many things have happened today and Miyuki had felt considerable stress. He thought it be best that he be there to comfort and reassure her but Tatsuya knew better than to voice this opinion. It would be improper for him to request to sleep in Miyuki's room, even if he suggested that he sleep on the floor, Tatsuya was a proper gentleman and he would never ask that of a young lady, especially Miyuki. He also knew Miyuki would probably not reject him if he asked. After Miyuki's confession, all of her behavior had been put in a completely different light. Miyuki had worn revealing clothing at home, she would press herself against him, there was even once where she pressed her breasts against his back while in her underwear. Tatsuya realized, Miyuki had done all these things to get his attention, to make him see her as a woman and quite frankly some of these tactics had actually worked. Tatsuya could not suggest they sleep together, it would not have been appropriate.

As Tatsuya walked out the door, he turned to face Miyuki to greet her good night when Miyuki leaned in to kiss him on the cheek.

"Good night, Onii-sama~" Miyuki mischievously smiled. It was now Tatsuya's turn to be dumbfounded. He stood there motionless as Miyuki closed her door, lightly blushing as he touched the cheek Miyuki had just kissed.

"What have I gotten myself into?" Tatsuya thought to himself as he walked back to his room. He laid down on his bed, contemplating how best to handle the situation. He ran multiple scenarios in his head as he fell asleep.

A/N: Hello! I recently reread the short stories Melancholic Birthday and Frozen Island and got inspired. It was clear to me that there was already romantic undertones in Tatsuya's thoughts in Melancholic Birthday and it seemed like he was only in denial. It was especially evident when he "regrettably, couldn't make Miyuki happy"and even lamented the fact that he could not marry her. This fanfic is heavily influenced by those two short stories and by vol 16 of the LN. I'm not sure if I want to keep this as a one shot or keep going and follow the main canon and just readjust it to accommodate their new relationship. This will be my second ever fan fic so if you have any comments or critiques feel free to leave a review. They are very much appreciated thank you!