ムキになる

向きになる

to become serious; to take something seriously (e.g. a joke, teasing); to become irritated or angry (esp. at something trivial); to get worked up

N3Expression
Expression, Godan verb (ru ending)
to become seriousto take something seriously (e.g. a joke, teasing)to become irritated or angry (esp. at something trivial)to get worked up

Example Sentences

何でもかんでもむきになってあくせくするのをやめれば、きっと(ひとびと)々は(いま)の2倍も長生きするだろう。

I'm sure people would live twice as long if they stopped getting themselves worked up over everything.