if (someone) doesn't come, have to come, must come
石田→私来なきゃよかったな
Ishida → Me: I shouldn't have come.
— 映画 聲の形 (2016)
お前らが来なきゃ俺は死んでた
If you guys hadn't come, I'd be dead.
— エリート・スクワッド (2007)
あなた達って、本当にここに来なきゃいけなかったの?
Did you guys really have to come here?
毎年ここに来なきゃ。
I have to come here every year.