By the time Kamiyā Yuu returned home, it was already close to midnight—far past Kamiyā Sora's usual schedule on school days.
—Which means she deliberately waited for me to come back before saying this. Then whatever she wants to say must be something she considers too important to delay until tomorrow.
Following Kamiyā Sora into the living room, Kamiyā Yuu flipped open his phone to check the time. Her unusual attitude made him recall what had happened over the past two days, and a faint sense of unease and confusion rose in his heart. Until now, he had always been the one controlling the pace of their interactions, but her unexpected actions had disrupted his expectations.
Once in the living room, Kamiyā Yuu noticed a neatly stacked pile of documents placed on the low table. Kamiyā Sora sat down in front of them and looked at him calmly.
Kamiyā Yuu scratched his head and said casually, "Sora, it's already very late. Can't whatever it is wait until tomorrow?" He knew the question was meaningless—it was just a routine way to start the conversation.
Kamiyā Sora shook her head stubbornly. "This matter is extremely important to both you and me. There's no need to delay it any further."
Kamiyā Yuu sat across from her, glanced at the documents on the table, and said seriously, "Alright, since you insist."
In the quiet living room, Kamiyā Sora hesitated, lowering her head as she stared at the worn file cover beneath her hand. After a moment of hesitation, she spoke softly, "Recently, you've probably noticed… the fact that we aren't actually biological siblings."
The words were like a bombshell, shattering something in Kamiyā Yuu's heart. Though it made his heart jolt, it also felt like he had long been mentally prepared. Frowning, he replied, "Yeah… I did. Yesterday, I used your hair and my blood for a DNA test. If nothing goes wrong, we'll have the results next Friday. But I didn't expect you to conclude me. Have you always known?"
"I don't want to keep hiding it anymore. I'll leave everything up to you to decide."
Kamiyā Sora bit her lip and nodded. After rummaging through the stack of documents, she slid a familiar photograph toward him. Beneath her silver hair, her gaze avoided his as she explained, "This is the photo you saw last time among Mother's belongings."
It was his parents' graduation photo. The only anomaly was that the woman holding his father's arm wasn't his mother, Kamiyā Kaoru, but an unknown woman whose head had been cut out.
"I found this photo in the box of belongings along with these documents before moving in. Since you never checked Mother's things, I kept some of the documents. The damaged part of the photo—I cut it out with a knife. I didn't want you to see what that woman looked like." Kamiyā Sora's expression turned calm, as if she were talking about something unrelated to herself.
Kamiyā Yuu picked up the photo, examined it, and sighed. "Why would you do something like that?"
Silence…
Kamiyā Sora shook her head. Her small hands tightly gripped the ruffled sleeves of her white gothic nightdress. Several times she tried to speak, only to stop herself. Finally, after releasing her crumpled sleeve, she said in a trembling voice, "You don't understand anything. Back then, you were my only support… my only family… my entire world."
"Yuu, back then, what was I to you?"
Kamiyā Yuu recalled those days and answered seriously, "No matter when, Sora has always been my only family—my irreplaceable younger sister."
Kamiyā Sora turned her head to look at a corner of the living room, murmuring absentmindedly, "That's exactly why I've always been so uneasy… both back then and now."
"When I was three, just because I said I was hungry at night, you snuck into the orphanage kitchen to get bread and milk. You fell from the high window and broke your right arm."
"When I was eight, because my hair color was unusual, the other children mocked me. You fought them alone. After that, no one in the orphanage spoke to you anymore, and they often bullied you together."
"When I was eleven, you used two years' worth of New Year's money to buy me this rabbit plush for my birthday."
"I remember everything you've done for me."
"When someone gains something, they inevitably lose something. Just like you said, you treated me as your everything back then. That meant my situation was the same. When you made me your whole world, then naturally, my world only had you left. You gave me everything… and also took away my entire world. So all I have is you—only you."
"If you leave me… I'll have nothing."
"Do you understand what it feels like to possibly lose everything? During the time I hid these documents, my heart was filled with anxiety, fear, disappointment, and pleading. I often dreamed that you would discover them… and then leave me." Kamiyā Sora spoke softly, her pale face and intense emotions making her seem as fragile as glass.
Kamiyā Sora was far more perceptive than most people, and her way of viewing the world was different. Kamiyā Yuu had accompanied her throughout her entire childhood, so all her memories naturally revolved around him. In her heart, he was everything—and she hoped he felt the same. Or rather, that was her pursuit and her happiness.
But the very act that created a crack in that relationship was her own decision to hide the documents about his identity. She had blamed herself countless times for that selfish choice.
...
Kamiyā Yuu recalled the time she mentioned—it seemed to coincide with when he had found a proper job, gained recognition, and moved out of the orphanage. Back then, he had just inherited his father's estate and received his mother's belongings. Kamiyā Sora had indeed been acting strangely at the time—she had spent several months climbing into his bed at night and often had nightmares. He had simply assumed it was due to difficulty adjusting to the new environment.
Kamiyā Sora pushed the stack of documents toward him. Her usually cool voice carried an unprecedented weight. "These are the documents I hid. After reading them… you should understand."
After doing this, she clutched the white rabbit plush tightly and fell silent. Although she had resolved to reveal everything, the thought that Kamiyā Yuu might leave her because of it filled her with unavoidable fear and hesitation.
From her restless demeanor and the way her fingers turned pale from gripping the plush, Kamiyā Yuu could clearly see her inner turmoil.
He nodded and began reading through the documents. Aside from a letter from his mother explaining his origins and offering some comforting words, the rest were things like his birth certificate and transfer documents.
Kamiyā Yuu's biological mother, like Su Yun, was a Chinese international student, and she and Su Yang were childhood sweethearts. Originally, they were considered one of the most well-matched couples among the Chinese students studying in Japan.
But things didn't last. His biological mother soon became involved with another wealthy second-generation Chinese student. After being completely used and then abandoned, everything fell apart. At that time, Su Yang—his nominal father—hadn't even so much as kissed her. After learning the truth, he angrily broke up with her and cut off all contact. During his period of heartbreak, he was comforted by one of his few friends, Kamiyā Kaoru.
Not long after graduation, Kamiyā Yuu's biological mother unexpectedly came back, begging Su Yang to help raise her child—him.
After much hesitation, the soft-hearted Su Yang agreed. In her letter, Kamiyā Kaoru didn't describe the details of how he came to that decision. She only wrote that while Su Yang was raising Kamiyā Yuu, she often came to help. Even matters like Kamiyā Yuu's Japanese household registration were entirely handled by Kamiyā Kaoru, who was still a young lady of a prominent family at the time.
From that point on, Kamiyā Yuu's biological mother disappeared completely.
As time passed, Su Yang and Kamiyā Kaoru developed feelings while raising him together. She ignored her family's opposition and married this poor Chinese student who already had a child. What followed was exactly as Kamiyā Yuu already knew. If one ignored the eventual outcome, Su Yang's life would have been a perfect underdog success story.
As for Kamiyā Sora cutting out the face of Kamiyā Yuu's biological mother from the photo, it was simply an impulsive act born from anger after reading Kamiyā Kaoru's letter. Ironically, in trying to hide his true identity, that action only made things more obvious.