expression
precisely because; exactly because
Emphasizes that the stated reason is the very cause of the result. Often used to justify or explain a strong conviction, action, or feeling.
あなたがいたからこそ、成功できたんです。
It is precisely because you were here that we succeeded.
難しいからこそ、やりがいがある。
It is exactly because it's difficult that it's worth doing.