I'm not sure if I understand but I guess..
Kure
= 그래
1. 그래? It is? (when you make a response..or ask in return)
2. 그래. Yes, It is.
actually it sounds more like G-RAE.
Kurom
=그럼
It could have a lot of meaning..
1. 그럼.. If so..(in the beggining of a sentence)
2. 그럼! Sure!
3. 그럼? So what? Then?
Sorry i don't know what kumayo means..