Okappiki were often prohibited by law in the Edo period, but Samurai did not know much about criminals in towns, so from the need for investigation, relative petty criminals were hired to collect information.
江戸時代には法的にはたびたび禁じられたが、武士は市中の犯罪者について不分明なため、捜査の必要上、比較的軽い犯罪者が情報収集のために使われた。