誰だれそれ

pronoun

a certain someone; Mr/Ms So-and-so

Used when referring to a person whose name is unknown or intentionally withheld; similar to 'what's-his-name' or 'so-and-so'.

• 誰だれそれから電でん話わがあったよ。

  There was a call from a certain someone.

• 誰だれそれさんが来くるって聞きいたけど、誰だれのこと？

  I heard that Mr/Ms So-and-so is coming, but who is that?