一石二鳥
いっせきにちょう
isseki nichou
= killing two birds with one stone / one stone, two birds
一石二鳥 (isseki nichou) is the Japanese equivalent of ‘killing two birds with one stone’ — achieving two goals with a single action. It is one of Japan’s most frequently used 四字熟語 (yojijukugo — four-character idioms), and mastering expressions like this one is a key step toward natural-sounding Japanese.
Isseki nichou (literally: one stone, two birds) is used exactly like its English equivalent to describe any action that achieves two benefits simultaneously. It is a yojijukugo — a classical Chinese-derived four-character compound that functions as a complete idiomatic expression. Common usage: 一石二鳥だ！(isseki nichou da! — It’s killing two birds with one stone!), 一石二鳥を狙う (isseki nichou wo nerau — to aim for two birds with one stone).
四字熟語 (yojijukugo — four-character idioms) are a distinct feature of Japanese and classical Chinese. Other common ones include: 一期一会 (ichigo ichie — once in a lifetime encounter), 七転び八起き (nana korobi ya oki — fall seven times, get up eight / perseverance), 十人十色 (juunin toiro — ten people, ten colors / to each their own). Learning a handful of yojijukugo dramatically improves the naturalness and depth of your Japanese writing and speech.
一 (ichi) = one. 石 (ishi/seki) = stone/rock. 二 (ni) = two. 鳥 (tori/chou) = bird. The metaphor is identical to the English ‘killing two birds with one stone,’ and the expression is thought to have entered Japanese from the English via Chinese translation during the Meiji era.
Everyday use
通勤しながら英語を勉強すれば一石二鳥だよ。
Tsuukin shinagara eigo wo benkyou sureba isseki nichou da yo.
If you study English during your commute, you’ll be killing two birds with one stone.
Casual / Social Media
ジム行って筋トレしたらサウナも入れた！完全に一石二鳥
Jimu itte kintore shitara sauna mo haireta! Kanzen ni isseki nichou
Went to the gym to work out and got to use the sauna too! Totally killing two birds with one stone
Formal / Cultural context
社員食堂における地産地消の取り組みは、食材費の削減と地域農業の振興という、いわゆる一石二鳥の効果をもたらすものとして評価されている。
Shain shokudou ni okeru chisan chishou no torikumi wa, shokuzai-hi no sakugen to chiiki nougyou no shinkou to iu, iwayuru isseki nichou no kouka wo motarasu mono toshite hyouka sarete iru.
The local food initiative in the company cafeteria is evaluated as achieving what might be called a two-birds-with-one-stone effect: reducing food costs while promoting regional agriculture.
四字熟語 (yojijukugo) occupy a unique place in Japanese language and culture. These four-character expressions — imported from classical Chinese (漢文, kanbun) and adapted into Japanese over centuries — function as dense, elegant shorthand for complex ideas. They appear in formal writing, news headlines, political speeches, and everyday conversation alike, and a person’s command of yojijukugo is often taken as a signal of education and cultural literacy. Japanese high school students study hundreds of yojijukugo for university entrance exams.
一石二鳥 is interesting because its origin is actually English — ‘killing two birds with one stone’ was translated into Chinese and then adapted into Japanese as a yojijukugo, giving it the classical appearance of a Chinese idiom despite being a modern borrowing. This kind of cultural absorption — taking a foreign concept and re-expressing it in classical Japanese/Chinese form — is itself characteristic of how Japan has historically incorporated external ideas while transforming them through native aesthetic frameworks. The expression is now so naturalized that most Japanese speakers are unaware of its English origin.
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