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...

While Conan walks with Ran, Sonoko, and Sera along a road lined with cherry blossoms, Ran looks at the cherry blossoms and recalls how she met Kudo Shinichi. 13 years ago, Ran was being bullied by some boys in her kindergarten class. She was approached by Shinichi, who had just joined the school. During singing time, Shinichi suspects something is up when he notices teacher Efune staring at Ran the whole time. Later, he's suspicious when Efune show favoritism to Ran. Efune explains each of his actions, but Shinichi suspects Efun is plotting something...