Conan, Ran, and Sonoko go to a tangerine farm located in a mountainous region within the prefecture in order to pick fruits. Farm manager Terauchi Tetsuji scolds Sokono for carelessly picking and damaging his tangerines. Conan and his friends are treated to a variety of tangerine-based dishes at the Terauchi family home. At the recommendation of Tetsuji's wife Nobuko, they head up to the top of the mountain to watch the sunset. Just as they're finished watching the sunset, they see Tetsuji riding the agricultural monorail up the mountain, but...