Place it at the exact beat of the reveal, after the setup has built tension, then follow it with Anime Ahh to stretch the reaction before cutting away. For a failed surprise, use Awkward Moment instead as the next beat to shift the mood.
About this sound
This six-second clip catches anime character Mari Ohara letting out a bright, startled 'Oh my god!!' in a high, theatrical voice. The sudden lift in her tone makes it feel playful and over-the-top rather than genuinely alarmed, turning a small shock into a comic moment that lands best when the surprise is shared.