I was interested too so started googling.

It was probably a comment by mikekchar: https://news.ycombinator.com/user?id=mikekchar

According to this response by CaptainZapp (the GP) on one of his comments ( https://news.ycombinator.com/item?id=17004877 ):

  Hi Mike,
  About six month ago you helped me through the "minefield" of eating as a gajin in Japan.
  Let's call it a rousing success (it helps if you even like natto, but I digress).
  Let me state for the record that your posts are shear awesomeness in contents and the amount of information provided.
  Thanks!"

I couldn't find the original comment by "mikekchar", but when you google "site:news.ycombinator.com mikekchar japan" you find many interesting comments about Japan.