In the quiet mountain forest, a meandering stream sings a meandering song floating in this silent world. A girl who looked very young walked slowly to the stream, stepping on the fallen leaves accumulated over the years. She sat on a big rock next to her, lifted her black hair with her hands, and revealed a delicate face. She looked at the stream in front of her quietly. She didn't know how long it took before she got rid of her statue-like posture, reached out and slowly pulled out a yellow envelope from her backpack, "Brother! I'm afraid I can't do what you said. There may be something in this world that cannot be jumped out of." She took out a lighter and lit the envelope in her hand. As the envelope burned, the ashes fell into the stream little by little and drifted away with the current.