once upon a time
US /wʌns əˈpɑːn ə taɪm/
UK /wʌns əˈpɑːn ə taɪm/

1.
昔々
used at the beginning of a traditional story to signify that it took place in the distant past
:
•
Once upon a time, there was a beautiful princess who lived in a grand castle.
昔々、大きなお城に美しいお姫様が住んでいました。
•
The storyteller began, "Once upon a time, in a land far away..."
語り手は「昔々、遠い国で…」と語り始めた。