interjection
oof; whoops; eek
Casual exclamation used when one makes a small mistake, is startled, or feels a sudden discomfort. Similar to あっ or おっと but with a slightly softer, more drawn-out feel.
はっちゃ、またやっちゃった。
Whoops, I did it again.
はっちゃ、びっくりした！
Eek, you startled me!