覆水 ふくすい ぼん かえらず
fukusuibonni kaerazu

Expression

1. what's done is done; it is no use crying over spilt milk; spilt water won't go back into its tray — literal

Proverb
ことわざ、覆水 ふくすい ぼん かえらずと う。
kotowazani fukusuibonni kaerazuto iu.
The proverb says that what is done cannot be undone.
Other forms: