Translation guide
Describes someone who changes their mind, mood, or behavior unpredictably and often on a whim. Japanese has several nuanced terms ranging from neutral to strongly negative.
To describe someone whose actions or feelings change suddenly without apparent reason, often in a light or neutral sense.
A person whose mood changes easily; often used for someone who is cheerful one moment and sulky the next. Can be slightly negative but common in casual speech.
彼は気分屋だから、急に機嫌が悪くなることがある。
He's a moody person, so he sometimes suddenly gets into a bad mood.
Literally 'a person of shifting moods/interests'. Often used for someone whose romantic interests or hobbies change frequently. Slightly literary.
彼女は移り気な人で、好きなものがすぐ変わる。
She's a fickle person; her likes change quickly.
Describes someone who acts on a whim; can be neutral or slightly negative. Often used for spontaneous, unpredictable behavior.
あの人は気まぐれだから、約束を忘れることもある。
That person is capricious, so they sometimes forget promises.
To criticize someone whose capriciousness leads to broken promises, lack of commitment, or untrustworthiness.
An irresponsible person; emphasizes lack of accountability. Often used when someone's whims cause trouble for others.
彼は無責任な人で、急に予定をキャンセルする。
He's an irresponsible person; he cancels plans suddenly.
A person who is half-hearted, unreliable, or sloppy. Implies a lack of seriousness and tendency to change stance easily.
あの人はいい加減だから、仕事を任せられない。
That person is unreliable, so I can't entrust work to them.
To describe someone who acts purely on their own desires without regard for others, often changing plans to suit themselves.
A selfish or self-centered person. Often used for someone who insists on their own way and changes decisions arbitrarily.
彼女はわがままな人で、自分の思い通りにならないと怒る。
She's a selfish person; she gets angry when things don't go her way.
Someone who does as they please without considering others. Similar to わがまま but emphasizes disregard for social norms.
彼は自分勝手な人で、いつも自分の都合だけ考える。
He's a self-centered person; he always only thinks about his own convenience.
To use more sophisticated or written-style expressions, often found in literature or formal descriptions.
Literally 'a person of morning orders, evening revisions'. Describes someone who changes decisions or policies frequently. Very formal and somewhat rare in everyday speech.
あの上司は朝令暮改の人で、指示が毎日変わる。
That boss is a capricious person; his instructions change every day.
Someone who adapts or changes their stance quickly, often with a nuance of being opportunistic or fickle. Used in both positive and negative contexts.
彼は変わり身の早い人で、状況に応じて意見を変える。
He's a person who changes quickly; he alters his opinion depending on the situation.
The English phrase 'capricious person' is not commonly used in everyday conversation. In Japanese, it's more natural to describe the behavior or use a specific adjective + 人 (ひと). Direct translations like カプリシャスな人 are not idiomatic.
気分屋 (きぶんや) focuses on mood swings and emotional unpredictability, while 気まぐれ (きまぐれ) emphasizes acting on sudden whims or impulses. 気分屋 is more about internal emotional states, 気まぐれ about external actions.