Unlike the English "goodbye," which can be used daily, often suggests that you will not see the person again for a very long time, or perhaps never again.
Bye-bye : Very common in casual settings, especially among younger people. : sayonara_means_goodbye
The word's dramatic weight has made it a staple in Western pop culture: Sayonara - Definition, Meaning & Synonyms - Vocabulary.com Unlike the English "goodbye," which can be used
: The word is a contraction of the phrase Sayo de arunaraba (左様でありますならば), which literally means "If it is to be that way" or "If that is how it must be". Unlike the English "goodbye