more than one bargained for

idiomatic uncountable

(idiomatic) An unexpected and (usually) unwanted result of a decision or action.

Japanese Meaning

予期せぬ、しかも通常は望んでいない結果（行動や決断によって引き起こされた副作用のようなもの）

The policy change proved to be more than one bargained for, triggering supply shortages and angry customers.

その方針変更は予想外でたいてい望ましくない結果を招き、供給不足や顧客の怒りを引き起こした。

Sense（1）

(idiomatic) An unexpected and (usually) unwanted result of a decision or action.

This was more than he had bargained for, and he squeaked shrilly with the pain.