What does the three-line flower want to express?

Three-line flowers are well used in the play. It is even more sad. Parting.

The flower with three lines in the name of the song doesn't mean a flower, but a traditional Japanese musical instrument-Sanweixian, a three-stringed instrument. Most of the accompaniment sounds heard in the song come from this instrument. The voice of Sanweixian can be felt very gentle if you listen carefully, and this tender voice can easily remind us of the past. This kind of old songs is most needed to precipitate the heart in an era full of pop music.