内緒

• Reading: ないしょ
• Romaji: naisho
• Kanji breakdown: 内 (nai/uchi) — inside, inner; 緒 (sho/o) — cord, beginning
• Pronunciation: /na.i.ɕo/

Meaning

Secret; confidential; private. Something kept hidden from others.

A noun used adjectivally (with の or で) meaning 'secret' or 'confidential.' 内緒で (naisho de) means 'secretly/in secret,' and 内緒にする means 'to keep secret.' Extremely common in casual conversation — 内緒だよ (it's a secret!) is a staple phrase. Also written as 内証 historically. Less formal than 秘密 (himitsu), which sounds more serious or dramatic.

Examples

1. この話は内緒にしておいてね。 Keep this conversation between us, okay?
2. 親に内緒でゲームを買った。 I bought a video game without telling my parents.
3. 内緒の計画がばれてしまった。 The secret plan ended up getting found out.

Usage Guide

Context: daily life, friendships, family

Tone: conspiratorial

Origin & History

Originally from Buddhist terminology: 内 (nai, inner) + 証 (shō, enlightenment/proof), referring to inner spiritual realization. Over time the meaning shifted from 'inner truth' to 'something kept inside' — hence 'secret.' The kanji 緒 replaced 証 in common usage.

Cultural Context

Era: Classical

Generation: All ages

Social background: Universal