Translation guide
How to express 'top secret' in Japanese, from formal classified information to casual secrets between friends.
Describing information that is officially classified at the highest level, such as government or military secrets.
The standard term for 'top secret' in official contexts. Often used for classified documents or information.
That document is treated as top secret.
Top secret information was leaked.
Loanword from English, used in similar contexts but sounds more like a direct translation. Common in movies or spy stories.
This is top secret.
Literally 'highest secret', used in very formal or legal contexts, similar to 'top secret' classification.
Access top secret information.
Emphasizing that something must be kept absolutely secret, often in business or personal matters.
Common word for 'secret' in everyday conversation. Often used when asking someone to keep a secret.
General word for 'secret'. Can be used in many contexts, but to emphasize 'top secret', combine with intensifiers.
A set phrase meaning 'do not tell others', often used in formal warnings or on documents. Implies strict confidentiality.
Used when telling a friend something in a playful, conspiratorial way, like 'between you and me'.
Literally 'a story just for here', meaning 'just between us'. Very common in casual conversation.
Just between you and me, I heard she's quitting.
A secret story or piece of gossip. Often used when sharing something confidential in a friendly way.
I have a top secret thing to tell you.
極秘 (gokuhi) is for official, high-level secrets. 内緒 (naisho) is for personal, everyday secrets between friends or family. 秘密 (himitsu) is the general term and can be used in both formal and casual settings, but often needs intensifiers like 絶対 (zettai) to mean 'top secret'.
While understood, トップシークレット sounds like a direct translation from English and is less natural than 極秘 in formal contexts. It's best reserved for casual, playful use or when referencing spy movies.
This is absolutely top secret.
A top secret project
Please keep this matter strictly confidential.