@Stavue Kaba's hand looks just like Mimi's, so when the white guy saw kappa for the first time, he also said he liked his hands. In the dorm he used Kaba's hand for the copy and you can see a bloodline on the hand from the copy of Mimi.
@Stavue in chapter 26 the white guy said that Kapa's hand is precious and he should keep his hand with him. Eight years later, when he was about to go with the priests, he said he still had to pick something up and that would be kapa's hand after such a long time.