Tamiya, a pet detective looking for a runaway cat, is approached by a stranger at a pachinko parlor one day. The man predicts that Tamiya will hit the jackpot on his pachinko machine, and, lo and behold, it turns out to be true. The next day, Tamiya receives a request to find a pet. The woman who made the request turns out to be the wife of Goro Mouri, the strange man she met at the pachinko parlor yesterday. The woman asks him to find her missing cat, Lucky, and shows him a picture of an animal that does not look like a cat at all. After three days, Tamiya goes to Mouri's house to report his search, but...