張本人|ちょうほんにんchouhonnin[3]nakadaka (mid-high)

1. nounoriginator; ringleader; perpetrator; main culprit; person responsible
   このうわさの張本人ちょうほんにんはだれだ？↗

   Who is at the bottom of these rumors?

• Synonym元凶げんきょうWrittenA written/formal word. Covers the ringleader of a misdeed and also the root cause of a bad situation, while 「張本人」 stresses the person who set things off.
• Antonym無関係者WrittenA written/formal word for someone with no connection to the incident — the opposite of 「張本人」. Rarely used.

Use 「張本人」 for the person who set something off, as in 「騒ぎの張本人」 — it need not be anything bad. For the chief culprit or the root of the trouble, pick 「元凶」; 「無関係者」 is the opposite.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 事件じけんを首謀しゅぼうするその人ひと。首謀しゅぼう者しゃ。