After the tennis teenager Yukimura takes in the black cat Nana, he finds that life has entered the countdown, and in order to freeze the death progress bar, he signs a contract with the black cat and embarks on a journey to save the world. In the process, Yukimura teamed up with Conan to facilitate Opal and Kidd to join forces, and became the driving force behind superstar Kyoko, who almost died in the cruise ship incident.