The Glass Coffin {Il Dottore X !Little Sister!Oc}

Prologue

    "Big brother!! Big brother!! Look, look!! It's so pretty~" a high-pitched girl's voice said. A young teenage female who had light mint blue hair that reached her waist and bright crimson eyes filled with excitement at the holly bush that was planted in front of her. A young male a little older than her with short hair the exact color as hers and the same color eye too. They looked identical to each other. He smiled softly at his little sister's excitement. The girl stood up and asked, "Isn't it cool?!"

    "I know, Mizuki. Come on, we should get home before we freeze to death out here," the young male said. They both were wearing thick winter gear but it still didn't stop the Snezhnayan cold from making them shiver. Mizuki caught up to her older brother who took her by the hand and lead them both home.

    "Hey, big brother? Do you promise that no matter what happens, you'll always be there to protect me?" Mizuki asked in a saddening tone. The young male hummed and said happily, "So long as you promise to stay by my side forever."

    "I can't. Remember when I had to take myself to the doctor yesterday?" Mizuki asked. The male nodded as he stopped walking. Mizuki frowned and said, "I don't have much time left to live. All the things we promised as kids will have to be forgotten. I'll be lucky if I can even make it to the end of the year. He was shocked that it took this long for the physical symptoms to appear."

    Mizuki felt her brother let go of her hand before pulling her into a hug. He frowned and said, "Please, be lying. This isn't a funny joke."

    "I wish I was lying, big brother," Mizuki said as tears formed in her eyes. The young male gripped his little sister close. He slipped something from his pocket and cover his sister's mouth to keep her quiet as she tried to fight back. He frowned and said, "I'm sorry. But I can't let that happen. I can't lose you too."

    He used the golden syringe he pulled from his pocket to inject a temporary solution into her neck. Her eyes widened that her brother finally snapped and used one of his serums against her. Her vision darkened as she hugged him back lovingly. She smiled and said as her body grew weaker, "I love you, big brother."

    "I love you too, baby sister. I promise to find you a cure, no matter how long it takes," the male spoke as his sister finally went limp. He would have to make a stronger dose to keep her asleep until he found a cure when he got her back home. The male picked her up and carried her back bridal style as he didn't want her to freeze. He needed to find a cure for this. He promised he would.

    He took her to a backroom in his house which happened to be his lab and laid her down on the metal table in the center of the room. Picking up another syringe filled with the same blue liquid, but it was a little darker. The male went over to Mizuki and said, "This should keep you asleep and alive long enough for me to find a cure for you."

    He injected the serum and later took her to her room where he tucked her into bed. His ruby eyes filled with tears as he held her gently in his arms for a bit before pulling away. The male rubbed away his tears and got up as he walked to the door.

"No matter what I have to do, I will get you that cure. Even if it means having blood on my hands."