expression
a broken relationship can never be repaired; a divorced couple are never reconciled
Proverb meaning that once a relationship (especially marriage) is broken, it cannot be mended, just as a broken mirror will never reflect light again. The literal image is 'a broken mirror will never shine again'.
「破鏡再び照らさず」ということわざがあるように、一度壊れた関係は元には戻らない。
As the proverb goes, 'a broken mirror will never shine again' — once a relationship is broken, it can never be repaired.
Similar proverb meaning 'spilt water will not return to the tray', emphasizing that what is done cannot be undone, often used for broken relationships as well.
The proverb originates from a Chinese story about a broken mirror symbolizing a separated couple. The exact historical derivation is uncertain, but the phrase is conventionally associated with the idea that a broken mirror cannot be made to reflect again, hence a broken relationship cannot be restored.