かと思いきや
just when (someone) thought ~, but actually; I expected ~, but in fact ~
N1
Meaning
just when (someone) thought ~, but actually; I expected ~, but in fact ~
Formation
普通形 ＋ かと思いきや
Verb（辞書形／た形）+ かと思いきや
い-adjective + かと思いきや
な-adjective + だ + かと思いきや
Noun + だ + かと思いきや
Explanation
〜かと思いきや is used when the speaker expects one result, but the actual outcome is completely different or opposite.
The first part shows a natural expectation or assumption.
The second part presents a surprising or unexpected reality.
This grammar strongly emphasizes contrast and surprise, and is commonly used in:
narratives
essays
news-style writing
explanations of unexpected results
The tone is written, slightly dramatic, and expressive.
Easy way to understand
Think of it as:
“I thought it would be X… but it turned out to be Y.”
or
“Just when we expected ~, the opposite happened.”