昨日きのうの友ともは今日きょうの敵てき

expression

friends today, enemies tomorrow

Proverb warning that relationships can change suddenly; a close friend may become an enemy overnight.

• ビジネスの世せ界かいでは、昨日きのうの友ともは今日きょうの敵てきということがよくある。

  In the business world, it's often the case that a friend today becomes an enemy tomorrow.