The Yatagarasu's badge is a treasured possession of Kay Faraday, which she wears at all times to show off her identity as the great thief Yatagarasu. When she was attacked and lost her memory, Miles Edgeworth held onto the badge for her and used it to remind her of her real identity. Following his resignation, he kept the badge in place of his own Prosecutor's badge, though he returned it to Faraday once he was reinstated.
The Cohdopian smuggling ring's members were sent orders through distinctive black directives cards depicting the same design as the badge, only with a white color. The Yatagarasu used an inverted version of the card to confirm that an evidence the group stole and exposed to the media was indeed from them.