On days when the fog blanketed the city, a memory would vanish. People called this phenomenon the “White Plague.” Everyone forgot something—perhaps a name, the taste of a meal from the day before. Life carried on, but among them were those who lost all their memories.
When Yuma awoke, he couldn’t even remember his own name. A strange city stretched before him, and his mind was a blank slate. The only clue he had was a small silver key tucked into his breast pocket. Yet, he had no idea what it opened.
As Yuma wandered through the fog-covered streets, his eyes caught an old woman sitting by the roadside. Her gaze was sharp, and as soon as she saw him, she chuckled knowingly.
“So, you’ve come to find the door, haven’t you? Since you have that key?”
“The door?” Yuma asked.
The old woman shrugged.
“Somewhere in this city, there’s a door that fits that key perfectly. If you open it, you’ll learn who you are. But…”
“But what?”
“Remembering everything won’t necessarily make you happy.”
Yuma didn’t respond. He clenched the key tightly and began walking through the city. The fog disoriented him, but he kept moving, his resolve growing stronger with every step. As he walked, strange sounds reached his ears—a mixture of crying and laughter, voices he couldn’t recognize yet felt deeply familiar. Each sound resonated within him, touching something buried in his heart.
After what felt like an eternity, Yuma found himself standing before an old, rusted warehouse. He inserted the key into the lock. It turned smoothly, as if the door had been waiting for him all along, and creaked open.
What lay beyond was Yuma’s lost memories. The house he had grown up in, the faces of his family, friends laughing together. And finally—his sister, Yui, shrouded in fog before vanishing.
“Yui…” he whispered, her name breaking free as tears welled in his eyes.
“Have you remembered?” The old woman’s voice came from behind him.
“This is my past, isn’t it?”
“That’s right. Now, you must choose—will you carry these memories forward, or will you forget them again?”
Yuma closed his eyes, took a deep breath, and stepped forward. As he did, morning light began piercing through the fog.
