I think it is one of the expressions that is not used in other language very often. The feeling that we have with this word is "from me, too", "it is I who should say so", "the one who should say so is me", etc. For example: A: Nice to meet you. (よろしくおねがいします。) B: Nice to meet you, too. (こちらこそよろしくおねがいします。) A: Thank you so much. (どうもありがとうございます。) B: Thank you, too. (こちらこそ、ありがとうございます。) (It is I who should say "thank you".) I hope this was helpful.

Hi,nice to meet you. it means "chen kan"(in Thai). we use just like this; Thank you(ありがとうございます） not at all (chen kan)(こちらこそ）

Use after よろしく always helps.