Assyria

A cold, soul-piercing rain began to fall. In the distance, you see the familiar face of your visitor, who is waving her fan and calling you to her. When you approach her, she declares, "Hello, my pure-hearted friend, I need urgent help. My mother left a message for me before she died. I found it, but it contained shocking news: during my birth, my mother also gave birth to my sister, whose search must begin immediately. I trust you as a detective. Please help me find her."

You're the only person who can help me.