(formal) first-person singular pronoun: I, me

personal, private / secret

a personal or private matter / selfishness / privacy, secrecy / (women's speech, obsolete) a brother-in-law

Alternative spelling of 私達 (“we; us”)

private; mine

not necessary to; don't have to

Expresses gratitude or relief for something that happened in the past, a choice made, etc.

If only ~

It's good / okay to... / is fine

all's well that ends well