Conan, Ayumi, Genta, Mitsuhiko, and Haibara help out at the mini bird park of park administrator Kimishima Tomoshi. With the help almost over, Kimijima asks them to find the owner of the lost baseball cap. Conan and others found Katsumi Wang's home based on the clues left in the hat. The police officer there who was on patrol for burglaries warned Katsumi to pay attention. After hearing this, Conan and others decided to investigate the matter.