na-adjective, noun
serious; earnest; sober; grave
Describes a person, attitude, or situation that is not joking, lighthearted, or frivolous; implies sincerity and a focused, responsible demeanor.
彼は真面目な顔で話し始めた。
He began to speak with a serious expression.
Study seriously.
na-adjective, noun
Emphasizes a straightforward, unpretentious, and genuine character; often used to describe a person's nature or approach to life.
彼女はとても真面目な人だ。
She is a very sincere person.
真面目に生きることが大切だ。
It's important to live honestly.