Translation guide
The English word "naive" describes a lack of experience, wisdom, or judgment, often implying innocence or a tendency to trust too easily. In Japanese, there is no single perfect equivalent; the best choice depends on whether you mean innocent/pure, gullible, inexperienced, or overly optimistic.
Describing someone who is simple, innocent, or childlike, without negative judgment.
Means 'pure' or 'innocent', often used positively for someone untainted by the world. It can imply naivety in a gentle way.
彼女は純粋で、人を疑うことを知らない。
She is naive and doesn't know how to doubt people.
Means 'innocent' or 'childlike', often implying a lack of guile. Can be used for naive trustfulness.
彼の無邪気な質問に、みんな微笑んだ。
Everyone smiled at his naive question.
Describes an innocent, childlike appearance or manner. Often used for looks or behavior, not deep personality.
彼女のあどけない笑顔に心が和んだ。
Her naive smile was heartwarming.
Describing someone who is too trusting and easily fooled.
Literally 'easy to deceive'. A straightforward way to say someone is gullible or naive.
彼は騙されやすいから、気をつけて。
He's naive, so be careful.
Means 'soft-hearted' or 'pushover'. Implies naive trust that others take advantage of.
あの人はお人好しすぎて、すぐに騙される。
That person is too naive and gets tricked easily.
Literally 'sweet', but can mean 'naive' or 'overly optimistic' in thinking. Often used in phrases like 考えが甘い (one's thinking is naive).
Means 'simple' or 'simple-minded'. Can imply naivety when referring to a person's thinking.
Describing someone who is naive due to lack of experience, often in a specific area.
Literally 'not knowing the world'. A common term for someone naive about how society works.
彼は世間知らずだから、すぐに騙される。
He's naive about the world, so he gets tricked easily.
Means 'innocent' or 'naive', often used for someone inexperienced in love or social matters.
彼女はまだうぶで、恋愛経験が少ない。
She's still naive and has little romantic experience.
Literally 'blue', but can mean 'inexperienced' or 'green'. Often used for young, naive people.
Describing ideas or plans that are naive because they ignore difficulties.
Means 'too optimistic'. A direct way to call an idea naive.
彼の見通しは楽観的すぎる。
His outlook is too naive.
A common phrase meaning 'one's thinking is naive/overly optimistic'.
そんなに簡単に成功すると思うなんて、考えが甘いよ。
Thinking you'll succeed that easily is naive.
A colloquial, slightly derogatory term meaning 'naive' or 'half-baked'. Used for ideas or people.
純粋 (junsui) emphasizes purity and lack of corruption, often positive. 無邪気 (mujaki) is childlike innocence, often about behavior. 世間知らず (seken shirazu) specifically means lacking worldly experience, and can be slightly negative or pitying.
There is no single Japanese word that covers all uses of 'naive'. Using ナイーブ (naību) is a loanword, but it often means 'sensitive' or 'touchy' in Japanese, not 'naive'. Avoid it unless you mean emotionally sensitive.
彼女には純粋な魅力がある。
She has a naive charm.
That plan is too naive.
彼は単純だから、何でも信じてしまう。
He's naive, so he believes anything.
Your thinking is still naive.
そんな甘っちょろい計画では失敗する。
You'll fail with such a naive plan.