Why are Asians obsessed with knowing other Asian people's ethnicities for no particular reason?

There are many thoughts on this one. Many Asians are racist to other Asians, so they might want to know what type of ethnicity you are so they can feel better about themselves. Also, it's a marriage thing. If an Asian is interested in you, they will ask you what ethnicity you are to see if you and that Asian will match together. Most of the time, though, it's just for competition. For example, a Korean and a Korean will fight to the death to get everything than the other. And, for example, Koreans are usually full of it and will think they are better than you if you aren't Korean. It's not a fact- it's just an example since that's what my Korean friends tell me. All in all, I don't think they are 'trying' to be obviously racist, it's probably a bad habit brought down from their parents since I know Asian parents ask that a lot. Hope this helps, and I wasn't trying to be racist in any way.