Kare no jōdan o kiite, kurasu zen'in ga omowazu fukidashite waratte shimatta.

Hearing his joke, the entire class couldn't help but burst out laughing.

Donna ni tsurai toki demo, kanojo wa itsumo muri shite waraō to suru.

No matter how painful things are, she always tries to force herself to smile.

Hito no shippai o hana de warau yō na taido wa, kesshite yurusareru beki de wa nai.

An attitude of snorting in derision at someone's failure should never be tolerated.

Kare wa kinchō suru to, gomakasu yō ni fushizen ni warau kuse ga aru.

When he gets nervous, he has a habit of laughing unnaturally as if to cover it up.

Kukyō ni tatasarete mo, yūmoa o wasurezu ni waraitobasu tsuyosa ga hitsuyō da.

Even when put in a difficult situation, you need the strength to laugh it off without losing your sense of humor.

Akachan ga ureshisō ni warau sugata o miru dake de, higoro no tsukare ga fukitobu.

Just seeing a baby smiling happily blows away all my daily fatigue.