In the sunny season, Edogawa Conan (voiced by Takayama Minami), Maori Kogoro (voiced by Koyama Riki), Xiaolan (voiced by Yamazaki Wakana) and the partners of the Junior Detective Team came to Kyoto together. They are about to board the Aegis battleship of the Self-Defense Forces to experience the feeling of going to sea. During this period, they also met the beautiful and somewhat mysterious female Self-Defense Force member Fujii Nanami (voiced by Shibasaki Yuki). Who knows that the happy atmosphere will soon be replaced by panic. A broken arm is suddenly found on the battleship, and the disappearance of the Self-Defense Forces has caused panic and speculation in the military. It turns out that the mysterious spy X of a certain country has quietly boarded the Aegis, waiting for an opportunity to steal the top-secret information on the battleship. In order to find the hidden opponent, Conan and Huiyuan Ai (voiced by Hayashibara Megumi), Dr. Agasa (voiced by Ogata Kenichi), Hattori Heiji (voiced by Horikawa Ryo) and Toyama Kazuha (voiced by Miyamura Yuko) work together to fight against the spies...