Place it right after the on-screen mistake in an edit, before any reaction from other characters. Follow it with the awkward moment sound if the apology falls flat, or move straight to a tuturu sound to reset the scene to a lighter anime beat.
Over dit geluid
This short 1.3-second voice clip features Black Heart saying so sorry in a brief apology line. It gives a listener a playfully smug, lightly embarrassed feeling, as if the apology is offered without much regret at all. The line is from Hyperdimension Neptunia, where Black Heart is the transformed goddess form associated with that series.