臥薪嘗胆

がしんしょうたん
going through thick and thin to attain one's objective

Reading

Readingがしんしょうたん
n.JMdict
Kanji臥薪嘗胆

Meanings

  1. going through thick and thin to attain one's objective
  2. enduring unspeakable hardships for the sake of vengeance