Bu Ran was released in 2018 as a theme song for the Chinese fantasy drama Ashes of Love, performed by singer-songwriter Mao Buyi. Its title can be translated as Undyed, reflecting the drama's story of pure, enduring love untouched by the mortal world. The song became one of the most recognised tracks from the series, widely shared in fan edits, covers and short videos across Chinese social platforms. This short excerpt is often reused online because its gentle melody instantly signals romance and longing, even for viewers who have not seen the drama.