From Japanese 空 (kuu, ku) meaning "sky", 紅 (kuu, ku) meaning "crimson, deep red", 黒 (ku) meaning "black", 咋 (kuu) meaning "shout, chew, eat" or 来 (ku) meaning "come, due, next, cause, become" combined with 羽 (u) meaning "feathers" or 蒼 (u) meaning "blue". Other kanji or kanji combinations can form this name as well.