Rare bird.
"The Navy Distinguished Service Medal is bestowed upon members of the Navy or Marine Corps who distinguish themselves by exceptionally meritorious service to the United States government in a duty of great responsibility. To justify this decoration, exceptional performance of duty must be clearly above that normally expected, and contributes to the success of a major command or project. Generally, the Distinguished Service Medal is awarded to officers in principal commands at sea, or in the field, whose service is of a manner to justify the award. However, this does not preclude the award of the Navy Distinguished Service Medal to any individual who meets the service requirements".
Ideal placement of the medal (in accordance with rules of wear).
Admiral Kichisaburō Nomura treated his Navy Distinguished Service Medal as an Order https://asiamedals.info/threads/admiral-kichisaburo-nomura.23097/
Quite rare "Crown Prince's Voyage to Korea" commemorative medal.