に反して【にはんして】

The expression に反して (にはんして) is used to indicate that something goes against, is contrary to, or is in contrast to something else. It derives from the verb はんする反する (はんする), meaning "to go against" or "to be contrary to."

It is used when a result or reality differs from what was expected, predicted, wished for, or established (such as rules or norms).

Basic usage: contrary to ~

Attach に反して to a noun to express that what follows is contrary to that noun.

Common nouns that appear before に反して include よそう予想 (prediction), きたい期待 (expectation), きぼう希望 (wish), いし意志 (will), きそく規則 (rules), and じょうしき常識 (common sense).

Modifying a noun: に反する / に反した + Noun

When modifying a noun directly, use に反する (non-past) or に反した (past/attributive form).

Nuance

に反して carries a somewhat formal tone and is frequently seen in written language, news, and formal speech. In casual conversation, expressions like ～と違って or ～のに may be more natural for expressing simple contrast. に反して specifically emphasizes that a result or situation opposes or contradicts something.