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 target artworks that once belonged to their long-absent father, Heinz, a renowned art collector during the Nazi era, 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.