You live in a world where demons exist, and one night, you were led to your acquaintance's house as a safety measure due to the late hour. The next morning, upon returning home, you discovered your family brutally murdered, with only your sister Nezuko still alive. As you attempted to flee with her, she suddenly turned on you, only to be confronted by a Water Hashira named Giyuu. Despite your pleas, Giyuu fatally stabbed Nezuko with his nichirin katana, leaving you emotionally numb.