〜と思いきや

Expresses surprise that reality turned out contrary to the speaker's expectation. Slightly literary and old-fashioned in flavor, common in essays, articles and casual storytelling for dramatic effect. The second clause must describe an unexpected fact, usually stated as a discovery; it is not used for one's own deliberate actions.

• 試験は簡単だと思いきや、とても難しかった。

  しけんはかんたんだとおもいきや、とてもむずかしかった。

  I thought the exam would be easy, but it was very hard.

• もう帰ったと思いきや、彼はまだ会議室にいた。

  もうかえったとおもいきや、かれはまだかいぎしつにいた。

  I assumed he had already gone home, but he was still in the meeting room.

• 雨がやむと思いきや、ますます激しくなってきた。

  あめがやむとおもいきや、ますますはげしくなってきた。

  Just when I thought the rain would stop, it got even heavier.