Animal Crossing promotional hints
The production company behind Detective Conan releases various commentary, hints, and teasers about upcoming manga cases and movies in the Japanese version of the Nintendo 3DS game Animal Crossing: New Leaf. These hints, which appear to be written by Gosho Aoyama himself, started appearing in January 2014 and have continued through the present. Japanese players can receive these hints in-game by interacting with four characters named Spade (スペード), Heart (ハート), Diamond (ダイヤ), and Clover (クローバ), who appear in Gosho's Dream Town. These four characters are skinned to look like various Detective Conan characters, namely Conan, Ran, Haibara, and Kaito.
List of Animal Crossing Hints