Klulu and Kruru sound displeasing to the ear to the average English speaker, in my opinion.

I was a big fan of the name Cara, but since that is not really her name, it might be better to go with a sort of romanized version of the name with a minor modification to make it more pleasant to the North American audience.

What about Kururu?

EDICT J2EK[kururu][: 枢 n くるる (1) pivot hinge (using extensions on the top & bottom of a door that fit into cavities in the frame)/(2) sliding wooden bolt (for holding a door or window shut) :]