My wife's stepfather was a Navy Ensign at the very end of WWII after graduating from the USNA. He was part of the US navy officers and enlisted allowed to go aboard Japan's last remaining battleship the Nagato:
The Nagato was the pride of Japan's Navy and the command to attack Pearl Harbor came from the Nagato, as Wikipedia notes:
Admiral Isoroku Yamamoto issued the signal "Niitaka yama nobore" (Climb Mount Niitaka) December 2, 1941 from the Nagato at anchor at Hashirajima to signal the task force in the North Pacific to proceed in its attack on Pearl Harbor, committing Japan to the Pacific War.
The former Ensign wrote up an account of how he got the relic: a brass door sign that two people have translated as being for a "fire control" room. I've often wondered whether that meant fire fighting, or fire control for the ship's guns?