Conan and his Detective Boys who came to the park for bird watching start observing humans on the other side of the river with binoculars to "improve reasoning power". While playing with a profession, He finds Detective Takagi in disguise staking out. Apparently, cash is being handed over in the kidnapping case. He tries to go to the other side, but it takes time to move, so he keeps watching. After that, the criminal appears in the handing over the cash and is secured, but Conan gets caught. The criminal was not a kidnapping case, but a victim of a special scam. The Detective Boys begin observing the person who seems to be the criminal.