口裏を合わせる

• Reading: くちうらをあわせる
• Romaji: kuchiura wo awaseru
• Kanji breakdown: 口 (mouth) + 裏 (back/hidden) + 合わせる (to match/align) → to align hidden speech, coordinate stories
• Pronunciation: /kɯ.tɕi.ɯ.ɾa o a.wa.se.ɾɯ/

Meaning

To get stories straight; to coordinate what everyone will say so the accounts match — often implying something shady.

口裏を合わせる implies coordinating testimony or explanations before facing questioning — whether from parents, bosses, or authorities. While it can be innocent (friends agreeing on an excuse), it often carries suspicious connotations. Common in crime dramas and news coverage of scandals, it suggests deliberate concealment of truth through coordinated storytelling.

Examples

1. 先に口裏を合わせておかないとバレるよ。 If we don't get our stories straight ahead of time, we'll get caught.
2. 二人の証言が完璧に一致してて、明らかに口裏を合わせてる。 Their testimonies matched perfectly — they obviously coordinated their story.
3. 口裏を合わせる暇もなかったから正直に話すしかなかった。 We didn't even have time to get our stories straight, so we had no choice but to tell the truth.

Usage Guide

Context: drama, news, gossip, planning excuses

Tone: conspiratorial, suspicious

Do Say

• 口裏を合わせてたのがバレて余計に怒られた (We got caught coordinating our story and got scolded even more)
• 口裏を合わせる余裕もないほど突然だった (It was so sudden there wasn't even time to get our stories straight)

Don't Say

• 真面目な場で「口裏を合わせよう」と冗談で言うと本当に疑われる (Jokingly saying 'let's get our stories straight' in a serious setting will actually make people suspicious)

Common Mistakes

• Assuming 口裏を合わせる is always criminal — it can be used for minor social situations like friends agreeing on an excuse
• Not understanding the 裏 (hidden/back) component — it specifically implies hidden, coordinated speech, not open agreement

Origin & History

From 口裏 (the back of one's mouth / hidden speech) + 合わせる (to match/coordinate). Literally 'to align what's behind the mouth' — to coordinate hidden statements so they present a unified front.

Cultural Context

Era: Long-standing expression, common in crime drama and news

Generation: All ages

Social background: Universal

Regional notes: Used across all of Japan. Frequently heard in crime dramas, political scandals, and everyday gossip about coordinated excuses.