角を矯めて牛を殺す
(Tsuno wo tamete ushi wo korosu; “Straightening the horns, killing the cow”)

Definition:

A situation where trying to fix a small problem ruins the whole thing. The cure being worse than the disease. Hammering and pulling on a cow’s curved horns in an attempt to straighten them is only going to be bad for the beast itself.

Breakdown:

This saying comprises conjoined verb phrases. The first begins with noun 角 (tsuno), “horn(s),” marked by particle を (wo) as the object of verb 矯める (tameru), “to straighten,” “to correct,” which appears in conjunctive form. The second phrase uses を to take as its object the noun 牛 (ushi), “cow,” and the verb being done to the cow is 殺す (korosu), “to kill,” in conclusive form.

Notes:

Replacing 矯める with homophone 溜める, “to amass,” is of course an error. Replacing it with 直す (naosu, “to fix”), however, is perfectly fine.

This saying has a surprising number of synonymous phrases. My favorite are the ones declaring that trying to repair or polish a Buddha statue, or a Jizou statue, will break off its nose.

Example sentence:

「角を矯めて牛を殺したように、ソフトにちょっとだけ手を加えてみたら、途中でパソコンが不意にブルースクリーンになってしまった」

(“Tsuno wo tamete ushi wo koroshita you ni, sofuto ni chotto dake te wo kuwaete mitara, tochuu de pasokon ga fui ni buruu sukuriin ni natte shimatta.”)

[“As if I’d killed the cow by straightening its horns, when I tried tweaking the software just a bit, all of a sudden my computer went BSOD.”]