Hitomi Kisugi, along with her older sister Rui and her younger sister Ai, run a café called "Cat's Eye". The sisters lead a double life as a trio of highly skilled art thieves. They steal works of art which primarily belonged to their long-missing father, Michael Heinz, who was a famous art collector during the Nazi regime). Hitomi's fiancé is Toshio Utsumi, a young clumsy police officer who is investigating the Cat's Eye case. Despite being a frequent visitor to the café he is unaware of the double life of the girls. Hitomi regularly informs the police in advance about her next job, and then uses Toshio's research about the security surrounding the target to help plan the job.
At the end of the series, Heinz leaves a note for his daughters stating that he cannot reveal himself yet because the mafia may kill him, but he may appear in five years' time. However, the "Heinz" turns out to be the sisters' treacherous uncle Cranaff, who betrayed Michael years earlier. After losing a final bet to the Cat's Eye, Cranaff decides to atone for his sin by setting fire to the museum, killing himself. Hitomi eventually admits to Toshio that she is part of Cat's Eye and flees before he can arrest her. Toshio vows to track her down, attempting to "arrest" Hitomi at the airport with a wedding ring. He resigns from the police force and travels to America to find Hitomi, but finds that she has lost her memory due to viral meningitis. Toshio spends time with her until her memories come back, and the two rekindle their relationship.