〜こそ

Meaning

Strongly picks out the word immediately before it, highlighting it as being that very thing and no other. Expresses the speaker singling out and emphasizing what they consider most important. As in "this time for sure" or "this very thing," it conveys the feeling of "precisely this."

Examples

今度こそ必ず成功させてみせる This time I will definitely make it succeed.
こちらこそお世話になっております It is I who should be thanking you.
努力したからこそ、この結果が得られた It is precisely because I made the effort that I got this result.
あなたがいたからこそ、ここまで来られた It is because you were there that I was able to come this far.