Detective Conan OVA 9
In this OVA, Conan is sick and has to stay home with a cold. He overhears Sonoko Suzuki telling Ran to dump Shinichi and instead date Dr. Tomoaki Araide. Conan gets angry over this and he receive a phone call from Ai Haibara. She tells him that she has created an antidote for him to try out, for testing purposes. Conan takes the antidote and when he wakes up, he is Shinichi again! However, Haibara is gone, and everything looks strange... could he really be still Conan, but only ten years into the future? And also, what does this mean for the love of his life, Ran?