연속적인 명화 도난 사건이 세상을 떠들석하게 만들고 있었다. '캣츠아이'라고 자칭하는 범인은 범행 예고대로, 많은 사람들이 보고 있음에도 자정 12시에 대담한 범행을 반복하고 있었다. 단서는 전혀 없다. '캣츠아이'의 정체란… 아름다 세 자매인 '루이', '히토미', '아이'. 그녀들의 범행 동기란 실종된 화가인 아버지의 그림을 되찾고 그 소식을 확인하기 위해서였다. 그러나 거기에는 국제적 신디케이트 ‘홍룡단’의 그림자가 있다. '캣츠아이'에 최대의 위기가 다가오고 있다…!
After the events of the TV series, the 18 year old Yoko Godai has abandoned her special agent Saki Asamiya name to return to her normal life, and is now studying for college entrance exams. However, she accidentally bumps into a young man named Kazuo Hagiwara trying to escape from a group of hitmen, and learns that he comes from Sanko Academy, a private school located in a remote island known as Hell's Castle. The school is ruled by a former revolutionary thought to be dead named Hattori who is trying to brainwash students into terrorists to help him stage a fascist coup d'etat in Japan.
Kouhei Aizawa is a freelance cameraman who moves from Tokyo to Karuizawa with his roommate. He starts dating Kaoru, his roommate's sister as well as Noriko, the female head of a bosozoku.
Following in the footsteps of manga such as Doraemon and Obake no Q-Taro in that the alien Ganmo (who resembles a chicken wearing sneakers) sets out to help his adopted human friend Hanpeita.
