Shirabe
こちら こそ

こそ

Common particle
English jmdict
1
particle it is ... that ...;precisely;in particular;definitely;for sure;only (when, after, because, etc.)
emphasizes preceding word or phrase
辛抱こそ大事なんだ。
It's patience that counts.
2
particle although;while;it is the case that ... but
as こそあれ, こそすれ, こそするが, etc.
彼は年こそ若いが十分その仕事をやっていける。
Young as he is, he is equal to the task.
3
particle it is precisely because ... that ...;only because ...
after conditional -ba form of verb
君のためを思えばこそこう言ってるんだ。
It is precisely because I have your best interests at heart that I am saying this.
4
particle formal or literary term not at all;not in the slightest;absolutely not;never
after -nai stem of verb + ば
English jmdict
1
noun (common) (futsuumeishi) word usually written using kana alone kousso (African flowering plant, Hagenia abyssinica);kosso;cusso;koso;brayera

こちらこそ

Expression
English jmdict
1
expressions (phrases it is I who should say so
「はじめまして、ジェイムズさん」「こちらこそ、あなたにお会いできて、こんなに嬉しいことはありません」
"Pleased to meet you, Mr. James." "The pleasure is all mine. It's an honor to make your acquaintance."