When Yumi sees a news story about the shogi championship match, she learns for the first time that Haneda is a professional shogi player. Several years earlier, Yumi received an envelope from Haneda and was instructed not to open it until he had acquired "all seven." Haneda has now won all seven major shogi titles. Detective Sato reasons that the envelope's contents must be a marriage registration, but Yumi threw out the magazine she kept the envelope in that morning. They immediately head to the dump site, but the magazine is gone. Conan and the Detective Boys attempt to help Yumi find the envelope, but...

Kogoro takes Conan and Ran to the Beppu hot springs in Oita prefecture. Kogoro's true purpose is not to vacation but to find Nakadai Manami, the missing daughter of nakadai Electric's president. It's highly probable that Manami came to Beppu to see her ex-boyfriend Hayami Hiroyuki. Fortunately Kogoro is able to find Manami, and the president Nakadai, secretary Hosogai, and fiance Ehara all come to Beppu, but Manami is kidnapped. Meanwhile, Detective Sato and the police are pursuing an armed robber in Oita...