The series centers on the three Kisugi sisters—Hitomi, Rui, and Ai—who operate a café named Cat's Eye. Leading a double life, the trio acts as highly skilled art thieves, leaving cards bearing the name "Cat's Eye" at their crime scenes. They steal artworks, primarily paintings, that once belonged to their long-missing father, Heinz, a renowned art collector during the Nazi regime, hoping this will prompt him to contact them. Toshio, the police officer investigating the case, is Hitomi's fiancé. He also vows to capture and dismantle the Cat's Eye Gang.