Conan and his friends were playing Frisbee at the park, when a dog named Matsunosuke launched off of Conan's head and caught the Frisbee. Matsunosuke's owner, Kanae Asakawa, apologized and took Conan's jacket in order to get it cleaned after Matsunosuke left dirt all over it. The next day when Conan and the Detective Boys arrived at her house to get the jacket they met Kanae's friend Tomoko and see Matsunosuke in his dog house, asleep.

Kogoro is undercover at the Blue Parrot, because Yuzuki Fukui asked him to investigate on a weird sound she hears frequently. Conan joins him, saying that Ran is angry because Kogoro is not home. But a simple investigation in a bar becomes more dramatic when Chikafumi Usuda, an office worker, is found dead.