あ~

oh, ah

あ (marks a drawn-out, expressive sentence ending) + ~ vocalic prolongation
interjection Rare #31,792
oh, ah An interjection used to show recognition or realization; the tone and context affect its meaning.
JA: あ~、そうなんだ。
EN: Oh, I see.

あ~→

Ah...

— 映画 聲の形 (2016)

あ~ホント久しぶりだのう

Ah, it's been ages!

— Departures (2008)

あ~意地悪言ってる

Oh, you’re just being mean.

— Cosmic Princess Kaguya! (2026)

津波が来たあ~

A tsunami is coming!

— 崖の上のポニョ (2008)

あ~

Ahh...

— AKIRA (1988)