nikotto
A brief, bright smile that appears and then settles. Like a flash of sunshine — warm, genuine, and momentary.
💡A stranger helps pick up your dropped papers — 'She smiled nikotto and said thank you.'
彼女はにこっと笑って手を振った。
She smiled nikotto and waved her hand.
The teacher smiled ___ when I gave the right answer.
正解を言ったら先生が○○笑った。