Did you really read your offered site's text?
You did convenient pick up.
your offered site:
http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1487572729
在日の人間が次のようなことを言っていた。
「俺の母親は日本人。でも親父は、
「わしの一族は韓国では優秀な一族だ。だが
お前には日本人の汚れた血があるから、
一族を継げないと親父（つまりこのバカチョンの祖父）
が言っている。お前は本国では歓迎されていない」と。
「日本人の汚れた血のせいでおれはじいちゃんに
認められない」と言い放っていた。
しかし、韓国・朝鮮人ほど世界でまれにみる汚れた
血を受けぐ国民はいないことは自明の心理であろう。
The summary is that
A Korean's grandfather said "The grandchild's mother is Japanese that have dirty blood , so the grandchild can't be successor."
So, poster said "Korean is the one that is dirty blood."
Briefly, the poster speak in return"Korean's blood is dirty" because He was said in first"Japanese's blood is dirty"
The Korean who is the minority is vividly aware of the "blood", because ,or else, they can't keep their ethnic group.
But Japanese is usually don't be aware of it, because Japan is wall-to-wall with Japanese.
That is the reason why I think >>420 is a Korean's writing.
Did you notice the fact that the Korean's grandfather and father say"Japanese's blood is dirty"at your site?
The word "dirty blood "is familiar with Korean.
The word "dirty blood "is not familiar with Japanese.