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...

Conan and Sonoko arrive at a dojo in Osaka where Kyogoku is training. Takami, the master of the dojo, once provided Kyogoku with a great deal of help with his karate training. While Conan and Sonoko watch the children practice, Kajiyoshi shows up to get Takami's signature on their agreement. Operating the dojo has become difficult to the point that Takami has taken out a loan, and he is considering selling the dojo. Later, an important black belt is stolen from the dojo's display case. When Kyogoku is suspected of stealing the belt, he challenges Takami to a fight. If he wins, the dojo will remain open, and if Takami wins, he'll return the belt...