The protagonists of the series are the three Kisugi sisters—Hitomi, Rui and Ai—who run a café called Cat's Eye. The sisters lead a double life as a trio of highly skilled art thieves, leaving cards with the name "Cat's Eye" at the scene of their crimes. They steal works of art that belonged to their long-missing father, Heinz who was a famous art collector during the Nazi regime, in the hopes of him contacting them....