I was so shocked when some Koreans made racist remarks about dark skinned South East Asians. They even insulted SEA countries and cultures. Does this normally happen in Korea?

See a translation

Actually, every social including probably your nation is too hard to avoid the problem because of stereotypes, prejudices and differences.

We (my social) have racism against NEA (Japan, China, North Korea, etc..), SEA, and black people and LGBT and so on.
We have used disgusting and insulting expressions and discriminations to them especially SEA.
Although we know we must not justify it, we have said in order to make an excuse "You guys do too".

I know I do never represent us, but I want to apologize to you in place of us.
I'm so sorry for the insults, discriminations and whatever make you angry.
Even if you detest and blame us about the problem, I would understand.