korotto
Describes a sudden, complete reversal — changing one's mind instantly, forgetting something entirely, or falling asleep in a second.
💡A child who stops crying instantly — 'He was crying but korotto started laughing.'
さっきまで怒っていたのにころっと機嫌が直った。
He was angry but korotto his mood completely changed.
She was against the idea, but ___ changed her mind when she saw the results.
反対していたのに、結果を見て○○意見が変わった。